The door closed with a muffled thud, and the tap of long-expected footsteps rang out.

Finally, after hours of waiting, she was going to have her chance. Every sense on heightened alert, she crouched down along the wall to better see her target.

The dark-haired boy stood in the middle of the corridor, glancing quickly around him before changing into the cat. There was no doubt it was really him. She couldn't help but inwardly smile. He thought he was safe here in the dungeons, but he was wrong. All of Hogwarts was her territory, and Potter wouldn't be safe anywhere. The black cat glided along the stone wall and took off at top speed.

What naïveté. How could he think he was safe this way? He was slow, clumsy, and…alone. Really, this prey was too easy. Jubilant, she sped up, cutting the distance between them. And this imbecile still hadn't noticed her, but he was nervous now—she could sense it in the rigidity of his paws and his sudden acceleration. Stupid creature—what did he take her for? Always roaming around on the prowl, looking for trouble. Ah well, he was going to find it. And his headlong flight for the Gryffindor dormitory wasn't going to save Potter…Shadow…didn't matter which!

The black cat had good speed, though, she'd have to give him that. But it would be of little use; he didn't know the place like she did, and at the next turn she'd take advantage of the gap to waylay him and put an end to this chase that gone on too long. Potter had escaped her for far too long, but in a second she'd block his path and his retreat at the same time, and then…

"Mrs. Norris!"

Foiled again! Hissing with frustration, the cat stopped short, ending her pursuit a few inches from the oh so familiar robes of the Head of Gyffindor House. And that voice, alas, there was no way to escape it! Mrs. Norris knew it only too well.

From behind the red robes, a little black furry head with green eyes peeped out to look at her, his expression full of confusion and…was that a trace of shame?

Satisfied for the moment with the effect, the old cat turned her back to him and took off with dignity, her tail straight up and her manner haughty.

Behind her, the young black cat transformed into a rather indignant teenager. "Mrs. Norris! I can't believe it!"'

"Well, well, Mister Potter," McGonagall said with a small smile, "have you had a bit of a fright?"

"It's…I…it's unbelievable, I should've guessed from the start," Harry exclaimed. "It's been her all along, I'm sure of it. Ever since I came to Hogwarts, every time I went prowling about, something was following me. That was the exact sound."

"I'm not surprised," McGonagall agreed. "Mrs. Norris has her own distinct way of marking her territory, of showing she remains the supreme authority when it comes to cats in this castle. She accepts my authority reluctantly, but she makes all the students' familiars feel like they're only intruders. She's a true tigress!"

"And she's ruthlessly efficient," Harry said, recalling the numerous times he'd fled, unaware of her presence. "If I'd known…you think that…she would've fought me? I'm not sure I could stand up to her in that form. It would be a bit ridiculous."

"Oh, she'd give you a strict lesson if it had to come down to it, of that you can be certain. But Mrs. Norris isn't aggressive, and battles according to the rules are beyond her years. No, she's just trying to impress, and I must say she's hugely succeeded. Content yourself with groveling on the floor and making her understand she's won; that's all she wants."

"What a…she really deserves her name!" Harry roared.

But his Head of House smiled indulgently. "She has her quirks, but she's a brave cat. She doesn't wish you any harm, Harry, much the opposite. It was she who alerted her master the last time Loki attacked you. Without her, Severus and Remus mightn't have been able to intervene in time."

Shaken by the revelation, Harry tried to call to mind all the occasions when he'd heard the cat running behind him.

"Actually, I think she helped me more than once," he was quick to admit. "I probably owe her quite a debt. I'll do what you told me—she really deserves it. And this is her home here…so long as she stays out of Snape's rooms."

This time McGonagall laughed outright. "I doubt it. She and Severus have a long private history. It so happens that our Potions master sometimes needs cat hair at the most inopportune hours. And the first cat at his disposal happens to be Mrs. Norris, who's absolutely not cooperative! If you happen to see Severus stumble unexpectedly in the corridors, no need to wonder why—Mrs. Norris is never far off."

"Merlin," Harry said, his eyes wild. "Cat fur? I thought he was joking…"

"Oh, Severus never jokes when it comes to potions."

"I really hope so, because he's talked about cat eyes as well," Harry grimaced.

"Eyes, hmm?" McGonagall said, her own eyes sparkling. "In that case, perhaps it'd be best if we review a few survival techniques, what say you?"

"You mean in my other form?"

The professor smiled again, before changing into the tabby cat.

"Great," Harry said with a big smile before changing in turn.

The word was decidedly much bigger and more exciting from this point of view. Not to mention his keen sense of smell, his feline hearing and…

"Shadow!"

The voice in his head brought him in line. With a leap, McGonagall was off at top speed into the corridor, before rushing up a staircase. Without waiting, Harry followed her, relieved above all else to see his Head of House hadn't gone in the same direction as Mrs. Norris. Stride after stride, he caught up with McGonagall, who was leading the way with a disconcerting agility, before stopping suddenly behind a suit of armor.

"Smell that scent."

Intrigued, Shadow sniffed in the corner. The smell vaguely brought something to mind, but it took the sight of a few red hairs stuck on the armor for him to realize: "Crookshanks!"

"Exactly. This is his favorite place."

Hardly reassured, Shadow glanced quickly around him. There was no trace of Hermione's enormous cat…all the better. He wasn't at all certain that he wanted to meet him in this form.

"Crookshanks will do you no harm. He's very peaceable," McGonagall reassured him, sensing his nervousness. "Follow me."

Determined more than ever not to let himself be outdistanced, Shadow took off after her. Running in the corridors like this was exhilarating, but after having been chased by Loki, it was hard to give himself over completely to the game. Even more so when, just around a corner, he found himself face-to-face with a pair of surprised yellow eyes, only an inch from his nose.

Shadow leapt backward, but the animal opposite didn't retreat, and let out a growl that made all the hair on Shadow's back stand instinctively on end. A cat, he noted as he blinked: a gray cat who didn't seem much more confident than Shadow himself, but who was putting all his courage into assuming a terrifying demeanor. Without great success.

"That's enough. Peace."

The intervention of the Head of Gryffindor was enough to calm the two young cats, who were studying each other distrustfully out of the corner of their eyes.

"It's only Titus, Oscar Bradford's cat. He's very young and won't do anything to you."

Intrigued, Shadow crept closer to see the animal. Oscar Bradford? A Hufflepuff…a bit younger than he was. The cat seemed hardly more combative than his master. Spurred on my curiosity, Shadow stuck his nose into the gray cat's fur, trying to memorize the odor. But if Titus wasn't aggressive, he at least had his dignity: a quick swipe of his paw to Shadow's nose reminded him of his good manners.

"That is not done," McGonagall said with a hint of amusement. "Make his acquaintance first."

Make his acquaintance? With a cat? How to start?

As if in reply, Titus began to circle carefully around him as he meowed softly. Disconcerted, Shadow just watched him, sitting on his hindquarters, his tail wisely curled around him. The other cat sniffed at him from a distance, before flopping to the floor, where he rolled around with an enthusiastic purr.

"I think you've made a friend," McGonagall explained to him, obviously satisfied.

Still wary, Shadow finally crept closer and reached out a cautious paw toward the gray cat, who had stretched out to his full length. Titus definitely didn't seem all that shy, after the initial contact. Emboldened, Shadow inched even closer still to sniff at the cat. An instant later, he found himself pinned to the floor, in a grip that was as quick as it was effective. Wrapping his paws around Shadow's neck, Titus had turned the tables and now pressed him firmly against the corridor tiles. Shadow squinted as he saw the other cat get closer to his jugular, ready to call McGonagall for help, when a raspy tongue licked his jaw with a happy purr.

Blech. Cleaning himself by licking had already seemed disgusting enough, but this? How could he get out of this without offending his new friend? And seeing McGonagall's contented look, no help was coming from that direction either.

Gathering his strength, Shadow twisted to evade Titus' grasp, and then sought refuge behind his Head of House. Stunned but relieved, he watched McGonagall politely indicate to the gray cat that the cleaning session was now over. Alone at last, he couldn't help but ask the question. "Are they all like that?"

"Ah well, which would you prefer, Mrs. Norris or Titus?" the tabby replied, amused.

"All right, Titus," Shadow admitted.

"He's a Hufflepuff. Very friendly. Follow me."

Without waiting for an answer, McGonagall took off on her paws again at top speed, zooming through the maze of corridors. His mind put at ease by their friendly encounter, Shadow followed her with less anxiety. Before he had time to realize where they were, the Fat Lady's portrait had opened to let them inside. Without a password, he realized. That was a good thing to know…

Without a sound and with extreme discretion, the tabby entered the room, inspiring Shadow to do the same. Climbing nimbly up the edge of a tapestry, they quickly found themselves perched up high with an unobstructed view of the Gryffindor Common Room. Walking along a curtain rod as if it were a bridge, McGonagall went just as far as the tables where a few Gryffindors were working. Shadow followed her with careful steps, uncertain of his balance. But what he saw below made him forget his vertigo. Ron and Neville were there, playing a game of chess beside the fire. And they hadn't even noticed them, absorbed by their game…and their conversation.

"I still can't get over that he even dared," Ron grumbled.

"He was really the last person I would've expected to make such a blunder," Neville agreed, concentrating on his pieces.

"It was more a bout of hysteria than a blunder. I've never seen Malfoy so furious."

"I almost felt sorry for him," Neville confessed. "I honestly thought Professor Snape was going to kill him on the spot."

"Merlin, I don't have a lot of sympathy for Snape in the classroom, but I have to say I almost felt sorry for him as well. If there was anyone who didn't know about what's up with his powers, that's over with now. I wouldn't be surprised if Malfoy's back in his dungeon right now, for having made such a scene," Ron laughed softly.

"Still, it must be hard for him," Neville said as he moved a pawn. "He can't even work with the people in his House anymore; he'll be forced to stay in the staff lounge." He shuddered. "I'd prefer to take my chance with the Slytherins."

"He really seemed upset," Ron agreed. "I'm curious to see what Harry'll have to say. I'm sure something happened."

"He had good intentions; that's the worst of it."

"Deep down, it's rather logical," Ron said with a shrug. "Malfoy wanting to do something to help him? It had to end in catastrophe."

"I think he learnt his lesson," Neville smiled. "How many moves until check and mate?"

"Three, basically."

"Forfeit," Neville sighed. "Anyway, we have to go—time for History of Magic."

"I'm sure Binns won't notice if we don't go," Ron grunted.

"Maybe not Binns, but Hermione…"

That threat was enough, and the boys put away the chess pieces before heading for the door.

Frustrated, Shadow stayed on his perch for a moment, flicking his tail. He'd understood that he wasn't supposed to give away his presence just then, but his two friends' conversation had intrigued him to the max. So what had Malfoy done in Potions class? Obviously, he'd managed to upset Snape, which was a good thing. Or not. Now he burned with the desire to find the Man In Black, but he knew that it wasn't time yet. Patience…

Beside him, the tabby let out a little meow to call him back to reality.

"Be careful you don't fall from here. But it's a good place from which to watch discreetly," she let him know.

A bit too much so for Shadow's taste. How many times had the Head of Gryffindor spied on her students this way, him in particular? McGonagall, though, didn't seem to notice his sudden change in mood.

"And don't scratch the curtains or tapestries," she went on. "Shapen your claws on trees, or Severus' furniture. To jump down, pick out something soft."

Showing by example, she jettisoned herself gracefully onto one of the stuffed armchairs sitting opposite the fireplace. After an instant's hesitation, Shadow followed her, convinced he was going to break his neck…but there was no way he'd show himself a coward in front of McGonagall, though. To his great surprise, he landed softly on the cushion, before dashing off after the tabby again.

For a witch of her advanced age, McGonagall's vitality was definitely rather impressive, he groaned as he almost lost sight of her again. When she finally left him an hour later to go back to her classroom, Shadow had learnt more than one thing.

The first was that a cat's muscles could be especially painful after an hour of intensive exercise. The second was that he should in no way underestimate his Head of House. He'd also learnt how to wind through people's legs without getting stepped on, and in addition, how to make them stumble, which seemed to be one of Mrs. Norris' favorite tricks.

Seen from the size of a cat, Hogwarts held even more hiding places, and McGonagall had been delighted to reveal them to him. Picking out scents had become child's play, but for now he had a few worries over pinpointing the noises around him. Knowing Mrs. Norris was on the prowl should've sufficed to motivate him to keep up his guard, he thought as he headed back to Snape's rooms.

At this hour, the students were still in class, and it was easier to distinguish between Hogwarts' little sounds. A creaking suit of armor, the cracking of wooden stairs, laughter afar off, a breath behind him…

A breath! Shadow turned, ready to stand up to Mrs. Norris, or, more usual these days, to Loki. But what he saw left him momentarily disconcerted. Opposite him was a cat that looked amazingly like himself—black, with a pair of piercing green eyes that were brimming with fury. Before he had time to take a better look, the beast had jumped on him, landing a violent swipe of his paws on Shadow's shoulder. McGonagall had taught him many things, but not how to defend himself when faced with a furious cat. Not waiting any longer, he changed form. But as he felt his body try to stretch and take his human shape, his adversary jumped on him once again, this time cutting his nose. Taken by surprise, Shadow fell onto his four paws.

Four paws…that wasn't good. Heart pounding, Harry went for his second option: flight. He'd just failed at transforming, and he was at the mercy of an enraged cat, and of course, no Mrs. Norris around to arbitrate the conflict. Fighting panic, he ran with all his might towards Snape's rooms. Adrenalin refueling his strength, it was just a short distance onward until he came out in front of the professor's door As if regretful, his pursuer abandoned his path, clearly not inclined to face the owner of the place.

Relieved and pathetic, Shadow slipped into the rooms.

"There you are," the familiar voice greeted him. Relief wiping away the rest of his distress, the black cat literally threw himself towards the voice, landing clumsily on the Man In Black's thick robes.

"Shadow? But what…" Leaving his question hanging, Severus raised his wand and performed a brief diagnostic. Simple scratches… An Accio later and with a bitter sensation of déjà vu, he'd dabbed the cat's wounds with disinfectant and healing salve. It would seem, though, that these wounds had been inflicted by another cat—that was already reassuring. But seeing Shadow's state, his head buried in his robes and his heart racing, Snape knew there was something else afoot.

Still with the cat in his arms, he began to pace the room, murmuring comforting words. It took several minutes before Shadow finally relaxed and jumped to the floor, seeming exasperated. A second later, it was a boy standing in front of him, who then collapsed into a chair with a sigh of relief.

"I did it! Merlin, I did it!"

Lifting an ironic eyebrow, Severus took a step forward.

"Did what, then? Survived your first cat fight? Destroyed all the Gryffindor curtains?"

"You've seen McGonagall?" Harry asked without making a move to sit up.

"I came across her in the corridors; she told me you'd had an interesting lesson."

"Yeah. Very. Interesting, exhausting, all of that. But I would've liked if she'd got to the essentials more quickly."

"Meaning?"

"Cat fights," Harry said with a groan. "A horrible black cat attacked me in the corridor, just opposite the Slytherin Common Room. But that's not really the problem. I mean yes, it's the problem. I couldn't defend myself. But that isn't the most serious part; I couldn't transform either! He jumped on me, I was confused and…I couldn't do it. It was horrible, Severus. I don't know what to do."

With a sigh, Severus went for the first armchair and took a seat.

"There's nothing horrible in that, stupid child. Haven't I already warned you that Animagus transformations take months, sometimes years, to master?"

"But I'm already an Animagus," Harry protested. "And I thought I was done with this problem."

"You master transformations perfectly under normal circumstances, which is already an excellent thing. You've yet to master them equally in stressful moments, such as this one. Everything cannot work well straight away. You must continue to practice, like everything else. There's nothing worrisome about that."

"I think there is," the boy sighed. "It's at moments like these that I need to be able to transform on the spot."

Severus put a hand on Harry's knee. "We'll work on it. On that and other things. We'll begin practicing again today; I hope Minerva didn't wear you out."

"No," Harry lied as he straightened up. "In top form. You could just skip the warm-up."

"I see," Severus said with a slight smile, before handing him a phial. "Swallow this."

For an instant, the boy thought of asking what it contained, but deciding that he was risking upsetting his father, he drank it without comment. Beside him, Snape did the same, even though his potion looked different. Unable to resist, Harry got up to take a better look.

"What's that for?"

Severus rolled his eyes.

"Ten seconds too late. Progress. The potion you drank will allow you to concentrate better and focus your powers. No side-effects."

"No, I was talking about yours," Harry replied, irritated.

"Hmm. Nothing very important. A fortifying tonic."

"Oh." The conversation he'd eavesdropped on in the Gryffindor Common Room came back to Harry's mind. "How did your Potions class go?"

Nothing in the man's body language betrayed his tension, but Harry felt it in spite of everything.

"Like a joint Gryffindor-Slytherin class. Well, put on your most practical exercise clothes. And take your cloak; we're going to go for a walk on the moors."

Frustrated, but not wanting to push the matter, the boy nodded. He'd have plenty of time to ask Ron this evening. A moment later, he was back in a new outfit, the cloak on his shoulders still smelling like Madam Malkin's shop. Harry noted Severus' satisfied nod when he saw him, and couldn't help but smile. He'd missed these little moments. Vernon had worn the same expression when Dudley had got his new uniform, and…

Dudley. He didn't want to think about him. Dudley and his little friend, Dudley who wanted to know more about wizards, Dudley who maybe would've ended up becoming a real member of his family, if only…

A hand on his shoulder pulled him from his thoughts.

"Are you ready?"

Harry could sense Severus' concern, but surprisingly, the man didn't ask any questions.

"Yeah. Do we have to take the Floo?" he asked apprehensively.

"No need, we'll keep ourselves close to Hogwarts this time."

"In that case, can I cross the castle in my other form?"

Snape hesitated for a moment before shaking his head. "I understand that amuses you, but it would be good for people to see you walking about in your normal form. Certain of them might start to think you're hiding yourself."

"That has nothing to do with it," Harry protested, "it's just…oh, all right. I suppose for this once…"

But whatever he might've said, the boy realized as he headed for the great doors that it wasn't without a measure of nervousness that he navigated the familiar corridors on two legs. Despite Snape's presence, he couldn't help but glance quickly behind him, searching for an invisible enemy and trying to sniff out a threat. Unsuccessfully.

"Relax," Snape said softly as they crossed the entrance hall. "Nothing will happen to you."

That was evident. But the tension in his shoulders didn't go away, even after Dean and Seamus waved at him, and a dozen Hufflepuffs shot him encouraging smiles. It was only once they were outside the stone walls that Harry relaxed at last, refusing to look behind him one last time. Beside him, he could sense that Snape was bothered, but once again, he didn't say a word.

Yet, as they walked alongside the lake, the boy noticed the faraway look in his father's eyes as he viewed the slippery shore. The memory came quickly back to Harry.

"It was here McGonagall took the photo!" he exclaimed. "The one with my mother, when she pushed you into the water."

Severus smiled gently, his tender expression making him seem ten years younger.

"Exactly. I often came to study here, under this tree, for some peace. Lily knew it and joined me when she could. When we'd finish studying, we had a habit of walking on the shore a bit and talking about our day. Or more precisely, Lily talked about her day and I listened," he smiled.

"She talked a lot?" Harry asked.

"What do you expect? She was a girl," Severus replied. "As for me, I've never been very talkative, and Lily had no objections to making up for my lack of conversation. Of course, when I started to associate with people she didn't approve of…and vice-versa…those conversations became more strained."

"You criticized her? For going out with my father?"

"Evidently. I don't see anything surprising about that. From an objective point of view, and in hindsight, she certainly had better arguments than I concerning my associations. But at the time, your father and his friends were far from model students."

"I know," Harry said soberly. "But when the two of you got along, what did you talk about?"

"Everything, actually. At first, all our little discoveries, then of what we'd learnt in Potions and Charms. She was very gifted. She talked to me about her family as well, the books she'd read. We missed music during the school year. Lily was mad about Muggle rock. She had an entire collection of records that we listened to on a continuous loop during the summer."

"And I'm sure you hated them," Harry teased.

"You're wrong. Actually it was a shared interest. I simply didn't have the means of buying a turntable. I kept all your mother's records; you could listen to them at the house. These are old classics, but rather outdated, I think."

"I saw them," the boy recalled. "There were a lot of records that I know as well. Actually, there were some I really like. Led Zeppelin, for example. They're really good."

Severus gave a start, but didn't answer.

"And what was her favorite song?" Harry went on, unable to let go of the subject. It was the first time someone had really agreed to talk to him about his mother when she'd been his age…a thought that was both difficult to imagine and fascinating at the same time.

"Actually she had several," Severus replied. "She had a song for every occasion; she especially liked to dig into the Beatles. When she needed help, she'd come looking for me, singing 'Help'. 'Let It Be' she kept for times when she was depressed, but she didn't need any particular reason to go on and on about 'Penny Lane' and 'Imagine'. In general, she liked catchy tunes."

"But there was one she liked best," Harry insisted. "There's always one, especially when it comes to girls."

Snape smiled a bit sadly. "I suppose that would be 'Over the Rainbow.'"

"That's a good choice. That said, I never did get to see the end of the film; the Dursleys hated that Dudley watched it; they always found a reason to turn it off in the middle."

"The film?" Snape asked, intrigued.

"The 'Wizard of Oz'. That's where the song comes from."

"That's right," the wizard murmured, his eyes distant. "I remember. Lily adored it, obviously. She never missed a showing of it."

"So how does it end?" Harry asked, happy for the information.

"Well, as you might suspect. Dorothy goes home, and all of the characters get what they wished for…in a way. The film's theme was very moralistic."

"It's a child's film," Harry said with a shrug. "So what did the famous wizard of Oz look like? Was he a great wizard?"

"He wasn't a wizard at all. The man was a complete imposter, a coward and a manipulator. Which clearly didn't keep him from being forgiven. He managed to pull off a trick to…" Snape stopped a moment to think. "In fact, I think this Oz would've made an excellent Slytherin. So it's logical he won through in the end."

Harry couldn't help but burst out in laughter. "I'll have to see it!"

He stared at Severus, trying to figure out how the man was taking this plunge into the past. He was nostalgic, Harry noted, but there was a gentleness about from him just now that was rare for his father.

"And her books?" Harry went on then. "I saw she read Shakespeare. Very classic."

"Your mother was a great romantic," Snape grimaced. "She never got enough of sentimental stories, and she knew all of Shakespeare by heart, of course."

"I bet 'Romeo and Juliet' was her favorite."

"Well, no," Severus smiled. "It was 'A Midsummer Night's Dream'. In fact, she thought 'Romeo and Juliet' particularly stupid."

"And you?"

"I don't care for Shakespeare," the professor said soberly. "We never had the same tastes in reading, outside of magical subjects. Our only common reference point was 'The Lord of the Rings.'"

Harry let out a genuine laugh again. "You like that? Stories about hobbits, elves and magicians?"

"Why not?" Snape retorted. "What's more, the Dark Lord is defeated at the end. I find that a sufficient selling point in and of itself."

The sound of Harry's laughter was sweet to his ears. In the end, it'd taken little to distract the boy from his anxieties. Of course, there was no need to tell him that Lily had gone on and on about 'Honesty' when their relationship had begun to change. Nor that he himself had given her a cassette of 'Wild World' shortly before her marriage. Even less that they'd kissed for the first time to the sound of 'Just the Way You Are,' and that he'd listened to 'Highway to Hell' a bit too often for his own tastes, after their breakup.

No, Harry didn't need to know all that, no more than he needed to know that Severus had thought he was going mad from listening to 'Stairway to Heaven' after Lily's death.

The boy, though, seemed to sense the change in mood, and turned toward him with a frown.

"We're here," Snape announced, gesturing toward the hills with his chin. "You'll be able to train here without the risk of causing damage. No creatures venture out here, aside from Hagrid, and he's been alerted to our presence."

"I really have to go visit him," Harry reproached himself. "I haven't even stopped by to say hello."

"Yes, you have, you remember? We were the very first to see him again," Snape said sarcastically. "You're not going to see him on your own. I don't trust him just now."

"Hagrid isn't dangerous," Harry protested strongly. "He just makes…weird choices sometimes."

"Wonderful euphemism. But as long as Loki is around, it would be too risky. Hagrid is completely mad when it comes to that dog."

"He's not a dog," the boy sighed, "but I understand what you mean. Couldn't he come for supper one evening, in that case?"

Severus made a face. "We'll see."

He was grateful to be spared addressing the subject further by their arrival at the middle of the moor. A quick spell confirmed that the place was deserted; he turned to Harry.

"Good. To start, I'd like you to truly focus yourself. Consider the countryside around you, identify all the elements of it so nothing will distract you. What do you sense?"

For an instant, Harry was tempted to sniff at the wind, but he realized in time that Snape was talking about magic. Closing his eyes, he did what Snape told him, and sought out the traces around him. Unsurprisingly, he could sense the waves of magic coming from behind him, from the direction of Hogwarts, as well as faint traces around him, but nothing specific outside of Severus.

"Hogwarts behind, and us," he summarized.

"Good. Now, sense your own magic."

This exercise was more difficult, and Harry hadn't ever practiced it before. Closing his eyes again, he tried to reach inward and make contact with his powers. At first it was only an impression, like a humming; then a blend of vivid colors appeared to him, shooting through his veins and radiating out around him.

A mixture was bubbling, he realized, colors seemed to burst in every direction, merging one moment, clashing the next…everything was confused and violent, and didn't appear to be under any control. Flustered, he opened his eyes again and focused on Severus. Was it the same for him? Trying his best, he searched unsuccessfully, at first, through the energy emanating from the man. Then he felt as if a dam gave gracefully away, and without him knowing how, the colors flashed before his eyes again. Rather, one color. He wouldn't have known how to describe it, but this time it wasn't a violent maelstrom of energy. No, Severus' powers were calm, disciplined, and swirling peacefully within him…and around him.

Harry blinked. What exactly was he seeing? A second later, the colors had disappeared and only Severus' silhouette and the moor around him remained.

"Well?" the professor asked.

"That was…wow. Like I'd taken LSD."

"Pardon me?

"LSD. It's a Muggle drug," Harry explained.

"I understood that, thank you. I was simply wondering on which occasion you could've tried that substance," Snape retorted.

"None," the boy hurried to reply. "It's just what I read about it—the colors and all that. I felt like I'd…uh, well, you understand."

"I suppose," Snape agreed. Should the opportunity arise one day, he'd have to have Harry listen to 'Lucy In the Sky With Diamonds. Maybe…maybe not. "And what do you conclude from this?"

"That our powers are very different. Yours—or your energy, I don't know—are much calmer. And they work together as, uh, a group, I'd say. Mine are an all-out storm, and they seem to be fighting each other…I'm explaining this badly," Harry apologized.

"No, it's quite clear and very accurate. Your powers are disturbed right now, which is entirely normal. Absorbing Voldemort's powers, as well as the psychological shocks you've sustained recently, have disturbed your magical energy. Now it's a matter of channeling and disciplining them. Does that seem logical to you?"

"Yeah, totally," Harry murmured. "What happens when I use my powers? The colors I saw, they…keep, uh, fighting?"

"That's what produces the various effects you're able to see with your spells," Snape agreed. "Our goal will be to unify these energies so as to better control them, which is, in fact, one and the same thing."

"All right, that makes my head hurt," Harry moaned. "Where should I start?"

"Something simple. An Accio would be the very thing you need."

"Using what?"

Severus casually threw an empty phial into the grass. "Try that. Gently."

Focusing to limit the impact of the spell, Harry muttered the incantation. The phial came to rest in his hand with a satisfying and controlled force.

"Good," Snape said approvingly. "Do you recall the green trunk sitting in the entryway of my rooms?"

"Yes," Harry replied, intrigued.

"Summon it."

"From here? But it's miles away, and in Hogwarts. It's impossible…"

"Try," Severus replied calmly.

It was stupid, Harry thought, no one could do such a thing. But the professor certainly had something in mind, so…

"Accio green trunk!" he shouted, doing his best to concentrate on an image of the trunk.

A few seconds later, Harry's eyes widened as a whistling sound came from the direction of Hogwarts; he had just enough time to duck to avoid the chest sailing toward him with the speed of a small airplane. The bulky object crashed into the grass with a loud thud, and Harry turned around, both dismayed and frightened.

"Is that the trunk?" he asked stupidly.

"No, Potter, it's an owl that transformed itself to make you happy. Obviously, it's the trunk. Rather satisfying—controlling the force of an Accio at that distance was no easy task."

"I didn't really believe it," Harry confessed. "And now?"

"Now we'll take up again what we did at the Manor. Try to vary the intensity of your Lumos by aiming at that shrub."

A quarter-hour later, Harry was content when he finally got Severus' approving nod, indicating that he'd passed the exercise. Controlling the intensity of a spell with all these new powers was much more complicated than it'd been before. And the shrub, now as transparent as if it were glass, was there as a witness that this intensity could change a perfectly harmless spell into something unexpected and potentially dangerous.

"Am I going to have to test all the spells like that?" he asked resignedly.

"That would certainly be wise," Snape agreed. "Above all it's important that you control your powers well. Next time, we'll work on progressively extending the range of action of this spell."

"I hadn't thought of that. Can everyone do that? I mean, vary the range of a spell?"

"Not many people bother with that sort of detail. In truth, for most wizards, the variation would be minimal, and happens unconsciously when they incant. But in your case, we can't leave anything to chance. You must master all aspects of a spell. Now, something of a more offensive nature. Like the last time, I'll cast a Patronus shape and you'll have to stop it. Ready?"

Harry nodded, and without delay, Snape made a large, ghost-like dog surge from his wand; it began to run around them. First gently, then more and more aggressively, the boy undertook to hold back the specter as Severus watched attentively. Even if the professor let nothing show, Harry still felt intimidated, which only reinforced his determination to pass each exercise.

When Snape again signaled the end of the exercise, Harry felt heartened and calmer than he'd been when they'd arrived. Closing his eyes, he tried again to sense his powers.

The image took a while to appear, but it ended by bursting again into his mind, showing that array of colors streaming within him. But it seemed the different colors were fighting less now, content with bumping slightly into each other, at places intermingling.

Taking a deep breath, he turned to Severus. "It's better," he said. "My powers. I don't know how to explain."

"They're more orderly, I presume," Snape said for him. "That's an excellent thing. You'll feel less apprehensive with these conditions; these exercises will have to be repeated as often as possible. But now we're going to try something else."

With a flick of his wand, Severus sent the trunk Harry had Summoned a little farther away from them.

"I should've suspected it wasn't here for nothing," Harry murmured. "I bet I'm not going to like what's inside."

"Very likely not," Snape admitted. "In fact, this involves a Boggart."

"Bad idea," Harry said quickly, stepping back. "Not now. Really, Severus, this isn't the right time."

"Calm down," the professor said soothingly, "everything will be fine."

"No, you don't understand. Boggarts really have a bad effect on me. They turn into Dementors with me, and I really don't need that right now. Please, I'll prepare myself for the next time, but not today. All right?"

"Harry, this Boggart is much less powerful than you. From this distance, it won't be able to sense your fears, and transform. You, though, can manipulate it to make it become whatever you want."

The boy glanced hesitantly at the trunk. "I still don't think this is a good idea."

"I'll keep it at a distance and won't give it a chance to get near you," Snape promised.

The look that Harry turned toward him—in the space of a second—before quickly glancing elsewhere, was like the thrust of a knife into Severus. Harry didn't trust him. The boy didn't think him capable of restraining the Boggart. Ah well, Harry was wrong, and he was going to prove it to him.

"Ready?" he asked.

Ashamed, Harry nodded.

The boy was asking for forgiveness, Severus realized, and clenched his jaw. "When it comes out of that trunk, I want you to focus on giving it a particular appearance. To start, I suggest Ron Weasley. That shouldn't be difficult."

"Do I have to say 'Riddikulus'?" Harry asked reluctantly.

"Yes. Think beforehand of exactly what you want it to become."

Harry got into position, wand pointed toward the trunk. Snape could see the tension in him, but he nevertheless opened the chest, thus liberating the Boggart, which flitted out in a confused fashion, clearly displeased with how it was being treated. Severus immediately immobilized it and turned toward Harry.

"Now."

"Riddikulus," the boy murmured in concentration. For an instant, the Boggart's silhouette remained indistinct, before finally changing into a perfect image of the youngest Weasley son.

Surprised, Harry blinked. "That was easy," he announced, his voice heavy with relief.

"Very good. Now someone else. Dumbledore."

The boy nodded and incanted again, with more confidence this time. Unable to move, the creature had no choice but to submit to the spell and fidget in place, trying unsuccessfully to free itself.

When Harry managed two more new transformations, Severus went to him, lowering his voice. "That was very good," he said gravely and softly. "And now, Harry, I want you to go back. I want you to remember this summer and what happened at Privet Drive."

A glint of pain flashed through the boy's eyes as he stared at Severus with a mixture of surprise and betrayal. "What?"

"This summer. And all the ones before it. I want you to remember Vernon, Petunia and Dudley Dursley."

"They're dead," Harry said, looking away. "I don't want to remember. It's not worth it."

"And I think it is," Snape replied. "Vernon. All those times he belittled you, insulted you. Petunia and all the horrible things she told you about your parents. Dead in a car crash. Dudley, who always brought you trouble."

"He wasn't as bad as all that," Harry protested.

"Oh really? And the times your uncle was drunk, when he convinced himself you'd made some mistake so he could take it out on you."

"He was afraid."

"As were you. You were afraid, and you were alone. You were locked in that cupboard and you heard his footsteps as he came…"

"That's enough!" Harry shouted. "What're you playing at?"

Quelling the desire to cut the session short and comfort the boy, Snape went on. It was necessary. He didn't have a choice.

"It's not a game, Harry. Nothing is a game; their deaths excuse nothing. Remember Petunia's expression when she talked about your parents. Remember the night when Vernon came up to your room to tell you that Marge was dead."

Harry was trembling, Severus noticed. And underneath his sleeve, the Mark was throbbing painfully at the flash of anger and emotion that the boy was feeling. He was on the right track… Keeping the hypnotic tone that he'd mastered perfectly, Snape went on.

"Remember all those times when you didn't have the right to play, to eat, to simply be treated like all children have the right to be. Remember."

Given the boy's unfocused eyes and his shaking hands, he was ready.

"Do you see that figure there?" he said, pointing at the Boggart. "It's Vernon. That's him."

Harry looked myopically toward the creature, which quickly took the appearance of his uncle. His face red, the man was hurling insults in his direction, shaking a threatening fist.

"If I lay a hand on you, dirty brat, I'll make it so you'll never dare want to hurt my family! You freak, you don't deserve…"

"Concentrate, Harry. I want you to shut him up," the Potions master whispered.

"Silencio!" the boy shouted, dangerously pale. The Boggart fell quiet, but its lips continued to move.

"Apply yourself. You can do better than that. I can almost hear him."

"Silencio!" Harry bellowed again, his hand shaking as much from anger as from the emotion of the moment.

Surprised, the Boggart suddenly found itself without a mouth, and began to flail its hands as it spun around.

"That's very good," Severus said in a gentler voice. "Look at me. Vernon is no longer there. It's Lucius now. Lucius Malfoy, the one who locked you in that cell and made you live through those horrors."

Cursing himself for what he was doing, Severus turned Harry toward the Boggart again. Unsurprisingly, it had taken the shape of the aristocratic wizard, and sported a small smile full of contempt. Severus again strengthened the spell that immobilized the creature, sensing Harry's energy vibrating around him.

"All that he made you live through, everything that wasn't true…he must not do it again. Fight him, Harry."

"Expelliarmus!"

The wand and cane Lucius was holding flew far away from him, but that wasn't satisfactory to Severus.

"No! Really fight him! That won't be enough, Harry. Remember, remember what he did to you. Get angry and put him out of harm's way!"

"I—Incarcerous!" Harry shouted then, still without great conviction. His powers helping, the incantation was enough, and the figure found itself imprisoned and immobilized. Severus restrained a sigh and released the Boggart from its bindings. He'd hoped for more, but in spite of everything, he'd sensed the spike in Harry's anger, and that at least was a positive thing.

"That's good," he encouraged Harry. "Loki. Loki is in front of you now. He's tried to kill you over and over; he had Hagrid kidnapped, he hurt Remus Lupin. Because of him, you no longer feel safe at Hogwarts."

And the wolf appeared, very similar to the ghost dog that Snape had conjured earlier.

"Master it, Harry. You can do it; stop him before he hurts someone else."

"Impedimenta! Animagus revelio!"

Snape smiled. Harry had reacted quickly this time, and he'd pinpointed Loki's principal flaw: he didn't feel comfortable in his human form. The boy had finally passed into combat mode, his hands no longer shaking. This was perfect.

"Caput Mortuum!"

Severus blanched. How…where had Harry learnt this spell? He couldn't have…

His eyes glassy, Loki had been immobilized in front of them. Deeply soulless and with no response.

Swallowing with difficulty, Severus quickly broke the spell before turning once more to the teenager, who was staring wide-eyed at the Boggart. "Harry, it's not Loki anymore. It's Bellatrix. Bellatrix Lestrange. She killed Sirius Black."

There was no need for him to say more. A second afterward, in a whirlwind of cloth and hair, Bellatrix appeared, her eyes madder than ever, her wand raised.

"Expelliarmus!" Harry shouted.

"That's not enough!" Snape roared. "She doesn't need a wand to injure, to kill! Harry, do something!"

He shouldn't have. He knew he shouldn't have pushed the boy to the extreme, not after the events at the Ministry, not after this summer. He sensed the Mark on his arm flare up abruptly, whiting out his vision for an instant, as Harry's rage exploded all at once.

"Crucio!"

The curse hit the Boggart with a force that propelled it several feet backward. The air around them sizzled and vibrated like it had on the day Harry had absorbed the Dark Lord's powers; it seemed to Severus that the sky had darkened all of a sudden.

The spell stopped on its own when Bellatrix didn't get up again, and Harry stood there, arms dangling at his sides, his mind blank. A hand came to rest on his shoulder, and he turned, barely able to recognize the man beside him. As if emerging from a bad dream, he rubbed his eyes. The hand pushed him gently, and he let himself be led to the witch's body lying there on the ground. Severus bent down cautiously, wand in hand, and took her pulse. Then he stood up again, his lips pressed together.

"She's dead, isn't she?" Harry croaked.

"The Boggart is dead, yes," Snape replied tensely.

The boy took a step backward, unable to look away from the body, but refusing to stay near the professor. He'd pushed him to do it, he'd forced him to the wall, he'd provoked this…

"Why?"

Severus sighed, but didn't try to come closer. "There are several things to glean from this lesson. The first is that your powers, given the way you used them, can be a powerful weapon. Fueled by anger, they'll draw from their new source and respond in a heightened manner. Visualize your powers now, Harry, if you will."

Reluctantly setting his vague resentment aside, Harry obeyed. It took him longer this time to manage a clear image, the sound of his pounding heart keeping him from focusing. When the colors finally appeared, he could see that once again they were intermingling, almost woven together to form a powerful current…a somber one, he realized. Even though these colors had no known names, they made Harry think of coagulated blood, of anger, and of death.

Fleeing the vision, he shook his head and turned his reproachful eyes toward Snape.

"Why?" he repeated.

"You must learn to fight," Severus sighed. "You must learn to use this anger against the people who deserve it. I don't want you to be attacked again, captured, tortured, without being able to defend yourself fully. These powers can be a bad thing, but they can first and foremost save your life, Harry. You mustn't hesitate to use them to their full extent in defending yourself. Our world is brutal and sometimes merciless. Neither Lucius Malfoy nor Bellatrix will hesitate for a second. You must not give them that second. You mustn't give Loki that chance again. And the day when you find yourself facing Voldemort, you shouldn't hesitate to make use of the weapons he's given you, and put an end to all this."

"You want to make a murderer out of me," Harry murmured as he looked away.

This time, Severus moved to close the distance between them, gently taking Harry's chin in his hand, forcing the boy to look at him again.

"I want you to live," he said softly. "I don't want to ever go through what happened at the cemetery again. I don't want to lose you."

His ordinarily steady voice shook with an emotion that Harry had rarely heard in it, but it was the waves of sadness and fear coming from the wizard that made the boy smile weakly. That, and the intense love he felt wrap around him, communicated through that hand.

"All right," he murmured weakly. "But I have to say I don't approve of your methods."

The corners of the professor's mouth curled up slightly as he nodded. "That's not really a new thing. The Boggart disapproved as well, I'm afraid."

Harry cast a bleak look at the body that was beginning to lose its shape. "Is it really dead?"

Severus nodded. "Lupin won't be happy."

The boy shook his head. "You should've picked something else…something less…extreme."

But Snape stubbornly shook his head. "Your father didn't have his wand, the night Voldemort attacked your house," he reminded him. "He wasn't even able to try to defend his family. If only he'd had some instinct, or a bit more distrust. I refuse for you to inherit that from him, Harry. I don't want you to take things lightly. Gryffindor courage is one thing, but it must not turn into arrogance or stupidity."

Harry lowered his head, deep in thought. Severus had already told him this—the frustration and incomprehension in his voice expressing how much he held James' carelessness against him. If he'd acted differently, then maybe Lily would still be alive, Harry thought. Perhaps he would've grown up with his mother. And maybe she would've decided to give Snape another chance as well.

The boy turned suddenly to stare at his new father, watching his face as he tried to search his thoughts, but he didn't read any answers there. How many times might Severus himself have imagined this scenario? James sacrificing himself in Lily's place.

Harry shook his head. He still thought Severus' methods had been excessive, but he knew Severus was right. With these new powers of his, the time for carelessness was past, as this was about his magic.

A familiar hand came to rest on his shoulder, gently encouraging him to walk in the direction of Hogwarts.

"That's enough for today. I think the bell for supper has already been rung. I wouldn't want a famished cat coming to steal a chicken leg from my plate."

Thinking back over their day, Harry couldn't help but laugh. Yes, the times when he could use his powers carelessly might well be over, but for the rest of it, though… Oh well, Severus seemed determined to ensure that he enjoy his life in peace and quiet.

With a gruff gesture, he readjusted Harry's cloak so he was properly covered.

"Well, Mister Potter, what would you say to using your powers to protect us from the elements?"

The boy smiled. "It's Potter-Snape," he replied. Then, raising is wand, he said, "Stupefy!"

For an instant, it seemed the rain had been suspended in mid-air, just as he'd wished it. Then the sky, which had been dark before, suddenly became white, and a frozen flake landed on his hand.

Flabbergasted, he blinked. No, he hadn't dreamed of… Beside him, Severus let out that soundless laugh of his, his tired face suddenly more relaxed. Large snowflakes fell around them, quickly covering the ground.

"I…did I do that?" Harry asked.

Snape laughed again, squeezing his shoulder. "Remember what happened with Cave Canem when you cast this same spell at the Manor," he said.

Frozen. Oh. Harry glanced guiltily around him. "Is this a problem?"

"Only if you don't like snow," Severus smiled. "Otherwise, this would be a rather fine excuse for a good hot chocolate in front of the fire."

Chocolate? Did he like snow?

A second afterward, a black cat ran across the moor, chasing the snowflakes, all the while jumping at the Man In Black and leaving white marks on his cloak. Laughing softly, Snape watched the animal run everywhere, its fur disheveled. The training session hadn't turned out so badly after all.

A bit farther away, in Hogwarts' highest tower, the Headmaster set down his binoculars as he brushed a few snowflakes from his beard. No, the castle hadn't suddenly been enclosed in a snow globe for children.

But the two wizards he could see on the banks of the lake, one playing in the snow and the other watching fondly, had just made his day feel like Christmas. Smiling, his eyes twinkling more than ever, he turned to Fawkes.

"Sherbet lemon?"