In spite of everything that had happened, the reality of his situation didn’t fully hit Harry until he was completing a short writing assignment in the History of Magic. Hermione nudged him, tapping the upper right corner of his essay. He stared at the place he'd written his name blankly for a moment, until he saw his mistake. His arm weighed down like lead, he picked up his correcting quill and crossed out 'Potter.' His heart crumpled as he watched the name fade away into nothingness. Then he slowly scratched in the word 'Snape' over it. He stared at the name for several seconds, feeling like beetles were crawling down his throat.

Yesterday, Harry had gone straight to the headmaster after confronting Snape, and Dumbledore had confirmed what Snape had said: he was fully aware of the professor's past actions, and had done nothing to prevent Snape from ensnaring his mum and his other self. The headmaster even claimed that Snape regretted what had befallen his parents.

"He wants to act like James Potter never existed," Harry had scoffed. "I don't know what sick game he's playing at with my mum, but—"

"Harry," admonished Dumbledore. "I know that Severus loves—"

"Don't say it," said Harry bitterly.

Dumbledore was silent for a moment. "You have no memories of James Potter?"

"Just bits," said Harry. "From the dementors."

"And you do not consider the Dursleys family?"

"Hardly."

Dumbledore nodded, and fell silent again.

"So I'm not allowed to defend my dad, because I didn't know him? Is that it?"

"No, not at all. In fact, I understand why you need to protect your father's memory. But there are no enemies here."

And despite Harry's protests, the headmaster remained convinced of the purity of Snape's motives.

Harry had trudged back to the common room that morning to find a House Elf waiting for him, holding in his trembling hands a wand for the "young master Snape."

Harry sighed and pulled his eyes away from the new name written on the parchment. He laid the paper on the professor's desk and thought he heard it land there with a thud of finality.

"What's gotten into you?" asked George Weasley when Harry ran into the twins in the corridor after class.

"Potions is next," said Harry. He shifted his book bag and fell in line with the two as they walked. Ron was oddly distant with him, but the twins had taken to him well enough.

"You two fighting over Quidditch again?" said Fred.

George laughed. "Remember the time we tried to make Snape an honorary Gryffindor so he could unabashedly root for you during matches? We made him a hat with Gryffindor colors. Funny how he never wears it."

Harry plodded on in silence.

"I know what will cheer you up," said Fred. "Knock, knock."

Harry rolled his eyes. One difference he'd found in this world was that the entire school was obsessed with knock-knock jokes. He couldn't go five minutes without hearing one.

"Knock, knock," Fred repeated insistently.

Harry had also learned that the twins were the worst offenders, and would not let up until everyone had heard their latest invention. "Who's there?"

"Snape."

Harry's shoulders slumped. Of course. "Snape who?"

"That's Professor Snape, boy!" said Fred, whacking Harry on the back of the head imperiously. "Detention!"

Harry smiled in spite of himself.

"That's the spirit!" said George. They paused at the top of the stairs leading to the dungeons. "Knock knock."

"Who's there?"

"You-Know-Who."

Harry was already grinning. "You-Know-Who who?"

But George paused before the punch line, looking over Harry's shoulder. "Oh. Hello, Professor."

Harry's skin prickled and he smelled the sharp acidic tang that announced the Potions professor.

"What exactly are you doing?" asked Snape.

"Just escorting your young charge to class," said Fred. "We wouldn't want him to get lost."

"Indeed," said George. "Those dungeons are dark. And cold. The sort of environment where you need protective headwear. You wouldn't happen to have any, would you Professor? A nice hat, perhaps."

"I did have," said Snape. "But one night I was low on kindling. Move along."

The twins winked at Harry and hurried off to their own classes. But Harry's good mood had dispelled. Without looking at the professor, he moved toward the dungeon stairs. But a cold hand fell on his shoulder.

"Planning on throwing me into a wall again?" said Harry, his eyes still fixed on the stairs.

The hand was removed. "I should not have lost control." There was a pause, and then, "But you should do your best to accept this situation, regardless of how it came to be. You will regret it otherwise."

"Is that a threat?" said Harry, finally turning. But instead of the loathing and malice he expected, he saw only surprise.

"Just foresight," he said. "There is no point in fighting what you cannot change." He pushed at his hair, which was starting to acquire the greasy, wilted appearance Harry was used to. Faint shadows had appeared under his eyes as well.

"I'll take my chances."

Snape studied him for a moment. "You would." He nodded towards the corridor. "Class is in five minutes."

Harry left quickly, bumping into Neville when he reached the classroom. Neville looked startled at his expression.

"Just ran into the greasy git," explained Harry.

Neville's mouth fell open. "That's a bit harsh, don't you think?"

Harry stared at him. "You're joking."

"Well, it's just…when he starts looking like he hasn't slept or showered, you know what that means."

"What?"

"That he hasn't slept or showered." Neville looked at him like the implication was obvious. Then he brightened. "Oh, that reminds me of a knock knock joke…"

Harry hurried away to his seat. He had just settled in when Snape strode in clapping his hands together. "The instructions for Strengthening potion are on the board. What can replace the first three ingredients?"

Harry slunk down in his seat. Not only did he not know the answer, but he had come to despise being called on in class. He'd already gotten points deducted by McGonagall for snapping at her when she called on him using that name for the third time in Transfigurations. Then, after class, McGonagall had pulled him aside and taken him to task for being, as she called it, "sullen."

"Couldn't you just call me Harry?" he'd finally asked in desperation.

"I cannot show favoritism towards students," McGonagall had said kindly. "Especially you. Everyone knows the staff look on you as practically family. Some of us teachers have even changed your nappies."

"You've what?" asked Harry. He was horrified.

"I don't suppose you would remember," said McGonagall, smiling. "But we watched Lily and Severus raise you right under this roof," she pointed at the arched ceiling in the corridor near her classroom, "so of course we may be predisposed to be a little soft on you. Still," she said, straightening. "It wouldn’t be appropriate to show that in the classroom. We must treat you as every other student. Keep that in mind, Mr. Snape."

And with that, Harry had trudged off.

Snape clapped his hands again, and Harry jerked up from his slumped position in his seat. The man still showed signs of exhaustion, but projected an air of energy. "I'm waiting for an answer."

Harry glanced over at Hermione, expecting to see that Snape was avoiding her waving hand. But to his surprise, her hands were fidgeting with each other as she muttered something to herself.

"Yes, Mr. Longbottom," said Snape.

Harry craned his neck backward to see that Neville had his hand raised. "Shrivelfig, Sir. But it reduces the effectiveness of the potion."

Harry gaped at him. He'd never seen Neville volunteer an answer in Potions.

"Excellent, Mr. Longbottom. Five points for Gryffindor."

"Five…what?" whispered Harry, looking for Ron to share his disbelief. Ron was sitting a few chairs away, and looked blankly back when Harry caught his eye.

"Now," said Snape. "Who can tell me the brewing procedure for this potion?"

Hermione started a new round of muttering, her hands still twitching on her desk. Harry eyed them like they were dead birds. Her hand finally shot up into the air. Harry relaxed at the familiar sight.

"Ah, Miss Granger. You have something for us?"

Hermione nodded. "Stir in wide loops and with great might, until the brew turns chalky white."

Harry stared at her. He felt as disoriented as he had his first day here. "What is going on?" he whispered to her urgently.

She looked back at him. "What?"

"Not up to your usual standards, Miss Granger, but it will do. Everyone?"

Everyone in class dutifully repeated the rhyme. Harry glanced around him as though surrounded by mumbling ogres. "Why are we…?"

"It's a mnemonic device. You don't use them in your world?"

"I suppose. Just…why are you coming up with them?"

Hermione rolled her eyes. "I can only answer in rhyme, or he takes points from Gryffindor, even if the answer's correct. He says everyone learns the material better, and it makes me slightly less pestering."

"Mr. Snape." The name jabbed him in the chest. He turned around to see the professor, and most of the class, staring at him. "Would you like to share with the rest of us what you and Miss Granger find so fascinating?"

The class tittered, and Harry became acutely aware of whispers of "Dad" and "Junior." He wanted to sink into the floor. "No, Sir," he mumbled. He felt the dark gaze digging into his skin, but refused to look up.

"Very well," said Snape. "Now, who can tell me—"

"He's not getting points deducted?" asked Malfoy. "He's talking out of turn."

"You are also talking out of turn," said Snape, but his tone lacked bite. "And I would expect a Slytherin to understand the value of nepotism."

Malfoy frowned, but didn't argue further.

Once they started on their potions, Seamus Finnigan wandered over to Harry to ask a question, but stopped mid-sentence when he saw that Harry's potion was turning an alarming shade of puce. The student backed off and turned toward Neville, who offered him an answer about brewing with great enthusiasm and detail.

"I always knew Neville to be a bit absent-minded," Harry said to Hermione.

"Oh, he was here, too, his first year. Luckily he had two experts on memory to lend a hand. He's been mad for Potions ever since. Perhaps you can offer some tips on how to improve the memory potion he brews…" She glanced at Harry's bubbling liquid, which was now issuing wet burping sounds. "…or not."

At the end of class, Harry felt an odd sting as Snape stared down at his sickly potion in disappointment. He could tell from the homework in his bag that his counterpart had understood more of the complexities of Potions. Whoever this other boy was, Harry was clearly not measuring up in the eyes of the people around him.

As the days got closer to end of term, he settled into a routine of sorts. He deeply missed his mum, but he did not see her out in the school, and didn't dare visit Snape's chambers again. He made a few tentative gestures of friendship toward Ron, but their conversations were stilted. He spent much of his time studying with Hermione or talking with Lupin. It was on a sunny afternoon when he'd sought out Remus Lupin for company that he learned the professor wouldn't be returning to Hogwarts next year.

"Surely you can see that I put all of you in danger," said Lupin as the two of them meandered their way across the grounds. He stooped to pick a wildflower, twirling it in his fingers. "And there are other issues."

"More werewolf prejudice?"

"Mmm. Rather more specific prejudice than that. I was apparently too close for comfort this year, and I'm in danger of losing my visitation rights."

Harry tried to puzzle through that one.

"Speaking of which," said Lupin, "It looks like I'll be seeing you just a few weeks into summer."

Harry was surprised and delighted. "You've never visited me at the Dursleys before."

It was Lupin's turn to look puzzled. "The who?"

"The Muggle relatives I live with during summer break. You must at least know their name, if you're coming to visit."

Lupin scratched his head, the flower in his fingers bobbing dizzily. "Er, I don't know what family visits you've worked out, but I was planning on seeing you at home." A horrible suspicion crept into Harry's mind. He watched as Lupin turned to him, concerned. "He hasn't scheduled another trip during my visiting days, has he? He's supposed to let me know if he's canceling."

Harry slumped against a tree. "You visit mum and me at home. And these are scheduled by...Snape." His mouth was weary of saying the name.

"No, I schedule them. He just vetoes half of them. I mean really, 'only during new moon days of the month'? And submitting a blood sample to check for 'moon cycle irregularities'? I was put through less to get an appointment teaching Defense Against the Dark Arts."

Harry was only half listening. Lupin thought he was going to be living with Snape. He saw no means by which he could possibly endure that. Part of him had actually been looking forward to a summer with the Dursleys: no Potions class, no comments about his 'dad', no more being addressed by his teachers as 'young Mr. Snape'. He pulled himself from the tree and said his goodbyes to Lupin, then marched toward the castle.

"Strawberry twists," he said to the gargoyle so he could jump on the stairs. He felt like he'd been in the headmaster's office more in the past two weeks than he had all year. He'd been questioned and prodded and ensorcelled in multiple attempts to discover a way back home. And yet, in all that time, they'd never discussed his summer living arrangements.

But when he opened the door to the office, he saw that the headmaster wasn't alone. A familiar dark figure lurked by the window. His appearance had steadily declined over the past few days. His hung limply in thick drapes, and his cheekbones were sunken. Still, his glower at the interruption was indefatigable. But Harry plowed forward.

"Where am I staying this summer?" he asked the room at large.

Dumbledore entwined his fingers on his desk. "That is the question."

Harry glanced at Snape. "I'm not living with him."

"Yes, we were just discussing that," said Snape, moving towards a chair. "And I quite agree."

The headmaster turned and regarded Snape for a long moment. "I see."

Harry felt like he'd arrived for a boxing match and found a tea party instead. He stood there, catching his breath, as he struggled to find the argument he'd been ready for. "But…Professor Lupin said he'd be visiting me."

"Lupin is mistaken." Snape's eyes narrowed. "As he has been about a great many things. He will see only Lily on his summer visit." A smile shivered across his lips. "Although perhaps I shall cancel that appointment as well."

"Really, Severus, the restrictions you put on the man—"

"He's had more than enough unrestricted access to her this year." His face darkened. "Always timing his run-ins so that she would be unable to tell me afterward."

"I hardly think that was intentional. He's not as familiar with her cycles as you are."

"Why shouldn't he spend time with my mum?" asked Harry. "They were friends."

"No, Lily and I were friends. She barely tolerated Lupin and his lot."

"She must've done more than tolerate them, as she ended up married to one of his lot."

Snape ground his teeth and turned back to Dumbledore. "Lupin and I had an agreement. He's violating it."

"And with his resignation, it appears he is willing to return to that agreement. I’m only encouraging you to consider that sign of goodwill before denying his visits."

Snape grunted a reluctant assent before glancing at Harry. "A pity you won't see him this summer, but the law is rather strict about unescorted werewolves going near defenseless Muggles. Perhaps your adoptive parents have some silver bullets lying about?"

Harry ignored the obvious threat. "They're not my parents. Just relatives I live with."

"Forgive me. I assumed there was a deeper connection, since you're willing to abandon your mother in favor of them."

Harry set his jaw. "I'm not abandoning her. And who are you to say what's good for her and what isn't?"

"I'm the man who has taken care of her for almost thirteen years."

"If it weren't for you, she wouldn't need taking care of."

Snape's eyes wavered. "Not all of us can be as blameless as yourself." Harry watched the lines of his face harden. "But I accept my responsibility and do what I can to make her safe and well. My true son also understands what duty to family means. You, on the other hand…" He raised a skeptical eyebrow.

Harry's face heated. "It's not as though you've given me a choice. You won't let me near her."

Snape's mouth upturned slightly as he leaned back in his chair. "I'm not in the habit of allowing those with no self-discipline run about my home. You will be far happier with the Dursleys, who are apparently tolerant of your disobedience. Or perhaps they simply fear any magic brought on by your uncontrolled rage?" Harry felt guilt and anger flash across his face, and Snape nodded smugly. "I see. No, you couldn't handle the responsibility of being Lily's son."

Harry rounded on Dumbledore, clenching the edge of the headmaster's desk. "Can't you do something?"

Dumbledore had been watching the proceedings, his eyes gliding back and forth like a spectator at a ping pong match. "You wish to live with your mother and Professor Snape?"

Harry faltered for a moment, but the thought of his mum propelled him on. "Yes."

The headmaster's eyes skated to Snape.

"No," said Snape.

Dumbledore sighed. "Do not press me, Severus. I have been patient enough. Unlike you, I was not Sorted into Slytherin."

Snape eyed Harry reluctantly. "I want his assurance that he will obey me."

"I'll...try," Harry stuttered out.

"You'll try?" Snape sneered. "Why don't you try giving your word. Promise that you'll follow my commands and ask permission for your activities, as any son should." His face smoothed. "Or we can go to the dungeons right now. You can explain to your mum why your stubbornness will prevent you from seeing her for several months."

Harry's knuckles were white against the headmaster's desk. "Fine."

"Your word?"

He pitched his head up and down.

Snape stood, looking pleased. "Headmaster?"

Dumbledore nodded his head in dismissal, an unreadable expression on his face.

"I want to see my mum," said Harry. It was the least he could get out of this exchange.

Snape looked uncertain. "The last day of term is in four days. You shall see her then."

"No. Now. You just said we could—"

Snape held up a hand and made a show of pulling a tarnished pocket watch from his robes. He examined the face carefully. "Less than one minute. It is reassuring to know how long your word is good for."

Harry had the sudden image of Snape bursting into flames from the heat of his gaze. "Four days."

Snape acknowledged this with a mocking bow, then strode from the room. Harry's heartbeat slowed as he sank into a chair and stared dully at the headmaster.

"You could have said something."

Dumbledore steepled his fingers. "While I like to think I have some influence over Snape family decisions, I try not to overstep my bounds."

"He hates me. If it were up to him, I'd never see her again."

The headmaster's smile was gentle. "You underestimate him."

Harry wondered if the man had somehow Disapparated during the conversation. "You heard what he said."

"If I recall correctly, you arrived here believing you would not see your mother for several months. Now you shall see her in four days, and for the entire summer."

"Yes, but it took everything I had to convince him!" He looked into the placid blue eyes, and a tongue of suspicion licked at his mind. "Didn't it?"

"It may surprise you to learn that before your dramatic entrance, the professor was quite agitated. He was determined that, son or no, you would not be raised in the plodding cruelty of the Dursley household."

"That's not possible." He reviewed the conversation in his mind. "Why would he refuse to take me in if that's what he wanted?"

Dumbledore chuckled. "Because he's Slytherin."

Harry slowly realized he'd not only been bluffed into living with Snape, but into following his every rule to the letter. He had the strange sensation that he'd just endured a highway robbery.

Dumbledore crossed over to Harry and offered him a lemon drop. "Don’t feel discouraged," he said. "It happens to me at least once a year."