… and Sirius fell …

Harry gasped his way out of the familiar nightmare – again – waking in an unfamiliar room instead of his familiar cell at the Dursleys' house. It took him a few seconds to realize that he was actually in Ron's room at the Burrow, and that the repetitive drone drowning out the night insects was actually Ron's snoring.

Willing his heart to slow its pounding, Harry tossed aside the covers and stood up. His limbs were still shaking from the nightmare, and he grasped the bedpost at the foot of the bed, trying to steady himself as he gulped fresh air. In his mind's eye, he could still see Sirius' face…

Desperate to escape the vicinity of his bed, for it was somehow easier to blame the bed for the nightmare, however illogical it might seem, Harry crept barefoot across Ron's floor, trying not to trip over the jumble of clothes, shoes, and other sundry items which typically littered the floor of a room occupied by teenage males. He made it to the door and slipped into the upper level of the twisting stairway.

Although he'd thought only so far as getting to the bathroom to splash water on his face, Harry ended up feeling his way down, down, down the steps, easing around irregular corners in near-total darkness. Normally, once he'd gone to sleep at the Weasleys' comfortable home, he'd sleep like a log until morning and had never appreciated until now how very dark it was on a moonless night in the country. In contrast, Privet Drive had streetlamps to alleviate the nocturnal obscurity, turning the interior of Number 4 into a reasonably navigable gloom. But this…

Harry was almost to the ground floor before he realized he'd left his wand on the small table between his bed and Ron's. The Ministry of Magic did permit the use of a Lumos outside of school for students of all ages. Sighing, he made his careful way down the final flight of steps and padded toward the kitchen. Feeling his way through the darkness, he located the sink and dashed a couple of handfuls of water against his face. The water continued to gurgle and groan through the pipes after he'd turned off the spigot. Finally, he fumbled Mrs. Weasley's dishtowel from its hook and blotted his face.

Sirius…

Harry pulled one of the mismatched chairs from the kitchen table and sank down into it. He couldn't stop having the nightmare. He kept reliving the scene in the Department of Mysteries all day long, day after day, and he kept waking in a cold sweat night after night. He kept seeing Sirius' face … and superimposed over his godfather, Snape's sneering visage.

Snape.

Harry's fists clenched. No matter how he looked at it, no matter what the angle, no matter what Dumbledore said, it always came back to Snape. Sirius didn't have to die – shouldn't have died – but Snape had made sure of it.

Snape had hated Sirius and Harry knew why. And when the opportunity had come his way to rid himself of his schooldays nemesis, Snape had taken full advantage. Oh, sure, he'd alerted the Order as to where Harry and his friends had gone … EVENTUALLY. But how long had he actually DELAYED? That's what kept eating at Harry. Sirius needn't have died, if only Snape hadn't delayed. Harry had given Snape the information. He was sure Snape had understood. But had Snape ever tried to stop the members of the D.A. from taking action, knowing full well that they would inevitably try?

No.

After five years at Hogwarts, five years of Snape popping out of the woodwork in the most unlikely of places, five years of his perpetually spying on Harry, Ron, and Hermione – well... it just proved that Snape COULD have acted in time. If he'd CHOSEN to.

Which he hadn't.

Harry shrugged in the dark of Molly Weasley's kitchen. One tiny part of his conscience argued that he shouldn't have headed off to the Ministry, leading his friends into danger. Another tiny part of his conscience nagged that Sirius should have stayed at Grimmauld Place, where he was safe. But the main part of Harry's mind burned with anger, knowing that if Severus Snape had acted as quickly as Dumbledore CLAIMED he had, the entire disaster could have been prevented. When Harry thought back to Third Year and Snape throwing a screaming fit, desperate for Sirius to be Kissed by a Dementor - no, there was NO WAY that Snape had acted as quickly as Dumbledore said he did. Snape WANTED Sirius to die. To be rid of him once and for all. As for the role played by Harry's faulty Occlumency … hell, it had been Snape's decision to end those lessons with Harry. Snape was the teacher – "authority" – and Harry was just a student. Absolutely – no matter how you sliced it, in the end, every piece of blame had Snape's name boldly emblazoned upon it.

The wooden chair scraped loudly across the floor as he stood up and headed for the sink again. This time, his fingers scrabbled through a couple of overhead cupboards until he found a tall glass, which he filled to overflowing with cold water. The pipes groaned and clanked again as he gulped down the water, but the cold liquid did nothing to quench the burning desire in his heart.

Harry wanted REVENGE.

He BURNED for revenge.

Revenge for Sirius.

And wouldn't Sirius himself have wanted revenge against Snape?

Harry clattered the empty glass into the sink, frowning. Deciding he was tired of sitting on the straight-backed chair at the table, he wandered toward the living room, banging his elbow painfully on a corner of the unseen china cabinet. Maybe he should have lit a candle after all, he grumbled, massaging his elbow. Then, leaning over, he patted the darkened air before him until he felt the arm of the sofa. Sighing in relief, he plopped down, allowing himself to be swallowed by the soft upholstery.

Revenge…

Nearly-Headless-Nick had said that Sirius wouldn't hang around as a ghost, Harry recalled sadly. It would've been … hmm … not "nice", necessarily, but … comforting? reassuring? … to still have Sirius available to him in SOME form, Harry mused. Even if Sirius were only a ghost. Although, he conceded, it was hard to imagine Sirius being "only" a ghost.

Imagine if Sirius were a POLTERGEIST!

Even Peeves would run for cover!

Harry chuckled in spite of himself.

And imagine – if Sirius were hanging about Hogwarts as a ghost or poltergeist, he could avenge himself against Snape! Sirius could HAUNT Snape! He could make Snape's life a greasy-gitty MISERY!

Harry closed his eyes, leaning his head back against the softness of the comfy sofa. He grinned in the darkness, allowing himself to envision the Potions Master's unrelenting demeanor cracking beneath the onslaught of an endlessly-vengeful Gryffindor ghost. Or poltergeist. Harry smiled. Cradled by the warm cushions, the youth fell into the first truly restful sleep he'd had in more than two months.

-:- -:- -:-

Snape's desperate dash through the greenhouses culminated in a confused scene involving a vat of bubotuber pus which smelled improbably of frying sausages and eggs…

Harry jerked awake, still hearing Sirius' wild cackle echoing off the steamy glass of the greenhouse windows.

"Sleep well, mate?"

Harry sensed Ron grinning at him through his freckles, but everything looked unaccountably blurry.

"I brought down your glasses and your wand," Ron announced, pushing something cold and wiry against Harry's fingers.

Automatically, Harry slid his glasses over his nose before grasping his familiar holly wand. "Thanks."

"So, why were you down here in the middle of the night without your glasses or your wand?" Ron wanted to know.

Harry sniffed the comforting scent of Mrs. Weasley's breakfast-making expertise drifting in from the kitchen. "Couldn't sleep," he admitted. He stretched several different ways before standing up. "But once I got downstairs, it seemed … easier."

"Hmm," was Ron's only comment. "Well, Mum should have breakfast on the table soon."

"Great!"

Both boys laughed as Harry's stomach rumbled loudly.

"I'll just dash to the bathroom first," Harry said, heading for the stairs.

"See you at the table," Ron called after him. "And don't forget – Hermione's coming over later."

-:- -:- -:-

The three Gryffindor soon-to-be-Sixth-Years clustered in a shady corner of the Burrow's back porch.

"Can you BELIEVE this?" Ron groaned. "It's not enough to just send our O.W.L. results. Oh, no – they have to send…" He threw up his hands in disgust. "It just ruined the rest of my summer!"

Even Hermione had looked taken aback to begin with, but she now pored over page after page after page of the additional enclosures which had come with the O.W.L. scores.

"We're N.E.W.T. students now, Ronald. It only makes sense that we'd be given a heads-up before school begins this year. I think it's wonderful that the teachers all sent syllabi for our prospective Sixth Year classes. Now we can see what we're facing before we choose our classes."

Ron groused something under his breath.

"What?" asked Hermione, regarding the redhead suspiciously.

"I said, you know you'll sign up for every class anyway, and besides, I haven't even finished my summer homework."

Hermione sniffed, tossing her bushy ponytail to emphasize her retort. "I'll bet you haven't even started it."

"Harry?" Ron looked to his friend for support. "Have you done your summer homework yet?"

The dark-haired boy nodded absently. "Most of it. For once, the Dursleys didn't lock up my trunk, so I did as much as I could before they could change their minds." He turned another page of the Charms syllabus. "I held off on doing anything for Potions until my O.W.L. scores came. Looks like I don't have to write the essay after all, since Snape will never let me in his class with just Exceeds Expectations."

"You should write it anyway, Harry," Hermione asserted from deep within her Arithmancy syllabus. "Just think of it as the end of Fifth Year work instead of the beginning of Sixth Year."

The boys shared a snort and an eyeroll.

"So, what do you think you'll take?" asked Ron morosely, poking unenthusiastically at his own pile of syllabi.

Harry pointed at Flitwick's requirements. "Did you see this? We have to INVENT a Charm this year."

"Really?" Hermione's head bent over Harry's syllabus, her eyes darting back and forth across the elegantly-printed lines. "Well, we can't just up and invent something out of the blue, you know. Professor Flitwick requires a prospectus and a conference, and he'll probably be supervising our efforts throughout the term."

Ron was staring at his own copy of the Charms syllabus. "What kinds of Charms haven't already been invented yet?"

Hermione took a sip of her lemonade, her forehead crinkled with thought.

"What about a Haunting Charm?" pondered Harry aloud.

Hermione spewed lemonade everywhere.

"HAUNTING Charm?" Ron's jaw had dropped practically to his chest. "Whatever gave you that idea?"

Hermione's brown eyes were about as wide as Harry had ever seen them.

"Forget it," he muttered. "Dumb idea."

Harry saw his friends exchange a Look, and somehow, he knew they weren't going to forget about the Haunting Charm. And neither was he.

If Sirius couldn't haunt Severus Snape the way the greasy dungeon git deserved, then Harry would just have to figure out a way to manage it himself.

-:- -:- -:-

By the end of the first week of Sixth Year, Harry was spending every spare minute in the Hogwarts library. Amazingly, he'd managed to enroll in N.E.W.T. Potions after all, thanks to the advent of a new Potions Master, Horace Slughorn. And thanks to the loan of a dilapidated but incredibly-annotated textbook, Harry's progress in N.E.W.T. Potions had delighted Slughorn and disgusted Hermione. And further thanks to the fact that Harry wasn't constantly blowing up cauldrons, he had far fewer detentions and far more time to spend on his Charms research. If ONLY he could manage to keep his mouth shut in Snape's Defense Against the Dark Arts classes…

"Potter!"

Speak of the devil.

"Hello, Professor," Harry said as politely as he could, given that he'd involuntarily jumped a mile when Snape spat out his name in the Restricted Section of the library. From somewhere beyond the stacks, he heard a distant "SHHH!" in Madam Pince's distinctive admonitory hiss. Keep calm, Harry told himself. Stay out of detention. Don't give him an excuse. Don't make eye contact.

"What you YOU doing in the Restricted Section, Potter?" demanded Snape, looming over the Gryffindor's table intimidatingly.

"Research, sir," Harry replied, continuing to copy notes from an oversized book. "For Professor Flitwick's class."

A black-clad arm reached out, and the Defense teacher snatched up Harry's sheet of inky parchment. "Chronological Delimitation," the odious man read aloud in a sneering tone.

Harry nodded, keeping his eyes firmly on the massive leather-bound tome. 'Yes, sir. Professor Flitwick assigned us an essay on how to effectively limit the duration of a Charm."

Snape slapped the parchment down on the oak table before Harry. "As it stands, Potter, your so-called ESSAY consists of sheer plagiarism. You haven't even attempted to include a fragment of originality. Plagiarism is grounds for expulsion, Potter, in case you haven't bothered to review your student handbook since First Year."

Beneath the table, Harry's fists clenched into painful balls of throbbing flesh. But he fought to keep his voice politely even as he replied yet again. "With all respect, Professor, this is not my essay. These are merely my initial research notes."

The tall man leaned down from behind Harry, planting a pale hand on the table on either side of the boy. "Is. That. So." he hissed against the back of Harry's neck, his hot breath causing the hapless Gryffindor to shudder despite his determination not to react.

"Yes, sir," Harry said stonily, wishing simultaneously that he could slug Snape with his aching fists and that Snape would go away so Harry wouldn't actually have to resort to physical violence.

The hovering man straightened abruptly. "I shall advise Professor Flitwick to be alert for any signs of plagiarism." Snape swept away from the table so quickly that the breeze from his robes caused Harry's notes to scatter across the table top.

"Git," the boy muttered under his breath when the insufferable man had truly gone. Harry's emerald eyes flashed angrily. "If I can just make this work, you'll get what's coming to you!"

-:- -:- -:-

By the third week of fall term, Harry had compiled the basic components necessary to create his Haunting Charm, but he still needed to pin down the various theories involved and figure out how to combine them in order to achieve the desired results. Flitwick's prospectus was due by the end of September.

It was Hermione who brought things into the open.

"Childrearing Charms for New Parents?" she read aloud, peering down into Harry's bag where the title was visible on the spine of the slender volume. "What on earth…?"

Harry glanced around quickly to make sure nobody was close enough to listen in as he, Ron, and Hermione sat near the shore of the Black Lake on a warm Saturday, golden afternoon sunlight glinting off the surface of the cobalt waters.

"But it's perfect," he said, pulling out the book. "See here? The Guilt Charm? It's in the category of Compulsion Charms. In addition to using specific Charms to get kids to eat all their food, or clean their rooms, or practice good hygiene, and so on, there's also a special Charm that parents can use to cause a child to experience a mild sense of guilt as a result of having done something wrong, or if they have failed to do something that was required of them."

Hermione frowned. "I can't say I approve of a – Compulsion Charm? – of any sort, especially when used against children."

Harry shrugged. "The Guilt Charm is actually a subcategory of Compulsion Charms. I guess it's up to individual parents, but I wouldn't use one on a child unless I had completely run out of other options."

Hermione smiled at him. "I'm glad to hear that, Harry."

"So, what ARE you going to use it for?" asked Ron, peering over Hermione's shoulder as she studied the page. "Who do you want to feel guilty and for what?"

Harry hesitated, then plunged ahead. "It's for Flitwick's class. Where we have to invent a Charm? It's one component of my 'Haunting Charm'. If I can get it to work out, that is."

Hermione frowned. "But Harry – we have to demonstrate that our Charms actually WORK. How can you prove that a 'Haunting Charm' works?"

Harry grinned widely. "I'll just have to cast it upon someone."

"Moaning Myrtle!" Ron guffawed. "It'd serve her right!"

Hermione smacked Ron's knee with the back of her hand. "Don't be mean, Ronald! It's tragic enough that she died. She was just our age, you know. Besides, you can't cast a Charm upon a ghost. Wizarding magic doesn't work like that."

"What about Lupin and Peeves? Remember that? Huh? How'd he do that, Hermione?" Ron demanded.

"I … um … you'd have to ask Professor Lupin," Hermione said quickly. "I can't explain it. It shouldn't be possible."

"Meaning you don't know everything after all," snickered the redhead.

Hermione's cheeks turned pink. "Go on, Harry," she tried to change the topic. "Tell us who your intended victim is. Malfoy?"

"He'd deserve it, mate." Ron's face brightened at the prospect.

But Harry was shaking his head. Once again he peered carefully around their vicinity for eavesdroppers before replying. "Snape."

Shaking her own head emphatically, Hermione declared, "No way. Professor Flitwick would never agree, Harry."

"The way I'll present it, I think he will," Harry argued.

Ron patted his best friend's shoulder commiseratingly. "It was nice knowing you, Harry."

-:- -:- -:-

Potter and his little friends were definitely up to something.

Severus Snape glowered at the Golden Trio as they sat down in the back of the Defense classroom. That in itself he found annoying. Even more annoying than their sitting as far away from him as they could get was the fact that all three of the Sixth Years had stopped making eye contact with him.

Oh, they responded politely enough when called upon – and were annoyingly well-versed in defensive spells when he required them to participate in class demonstrations. And, yes, they even volunteered answers – ALL of the Gryffindor half of the Defense class did, not just Granger. Yet, those three refused to look him in the eye.

Undoubtedly, Potter had warned them about Legilimency. But what, SPECIFICALLY, did they NOT want him to see?

"Potter!"

"Yes, sir?"

"On your feet." Snape beckoned Potter to the front of the classroom.

The boy squared off against the man silently, looking at Snape's wand hand, not looking him in the eye.

"Look at me, Potter," Snape ordered.

The boy raised his gaze slightly, and Snape could tell that his eyes were focused roughly at chin level on Snape.

Definitely … Up. To. Something.

Snape flicked his wand in disgust and frustration. A small boulder … well, a large rock, anyway … hurtled toward Potter.

"Reducto!"

The rock shattered and Snape flung a Shield Charm to protect the students in the front of the class from the flying fragments.

"Pathetic, Potter," Snape sneered triumphantly. "This is the final week of September, and you are as incompetent as ever in your non-verbal skills."

The boy glared at the front of Snape's many-buttoned coat.

Disgusting little cretin.

"Detention, Potter. Seven-thirty tonight. This classroom."

Potter glanced at him in surprise upon hearing the location, then remembered to quickly avert his eyes.

Snape smirked.

-:- -:- -:-

"Only if Professor Flitwick agrees, Harry. Only if he approves your Charms project. Personally, I think you have an ulterior motive in trying to create a Haunting Charm to use on Professor Snape, so I'll only agree to help you if your prospectus gets approved. I doubt that Professor Flitwick will actually approve it, but if – IF – he does, I'll try to help you. With the theory, at least."

"Thanks, Hermione."

-:- -:- -:-

"Again, Potter!"

Harry tried to stifle a sigh of resignation as he pushed himself to his feet for the umpteenth time.

Almost immediately, he was knocked to the floor, his silent "Protego" useless against Snape. At least the git wasn't hurling stones at him tonight. But the repeated Disarming Charms had left him bruised, sore, and angry. He'd glared at Snape a couple of times early on, only to yank his eyes aside when he realized it was Snape's INTENT to force a direct glare so that the man could Legilimize Harry. As a result, Harry had spent the past two and a half hours glaring at the floor, the walls the desks, the windows, the framed paintings – at everything BUT the Defense teacher himself. If only they'd been in Snape's dungeon office, Harry could have glared at each and every polished jar of disgusting Potions ingredients.

"Utterly pathetic, Potter."

"Sorry, sir. I'll try to improve."

"Practice, then. And to impress upon you the necessity of using non-verbal spells, I will see you in detention for one hour every weeknight, beginning at seven o'clock, until you manage to successfully cast a non-verbal spell. Understood?"

"Yes, sir."

"Dismissed." The intolerable man stood blocking Harry's route to the corridor door.

Harry was forced to walk around the Defense teacher's stony figure, the black robes seeming to vibrate with disapproval as the student departed the classroom.

But Harry's secret was safe. At least, for the time being.

-:- -:- -:-

"Professor SNAPE?" Filius Flitwick's voice squeaked his astonishment. "You propose to cast a – HAUNTING Charm – on Professor SNAPE?" Flitwick stared at Harry rather dubiously. "Mr. Potter, I'm afraid – "

"But don't you see, Professor?" Harry cut in with an apologetic gesture for interrupting. "Professor Snape would be the most perfect subject for this Charm. He's highly intelligent, not the least superstitious, extremely level-headed and self-possessed, and not at all given to undue paranoia – See, Professor, I would NEVER consider using this Haunting Charm against another student, especially when it's still in an experimental stage, but Professor Snape is virtually immune to external manipulation. If the Charm succeeds in 'haunting' him, even the slightest bit, his natural resistance will help prove the Charm's very effectiveness. See, sir?" Harry fixed his earnest emerald gaze upon the diminutive Charms professor.

Flitwick steepled his fingers consideringly, his lips pursed as he stared down at Harry's neatly-quilled "Prospectus for the Creation of a Haunting Charm".

"So, your basis for the 'Haunting Charm' is a Guilt Charm, a subcategory of a Juvenile Compulsion Charm?"

Harry nodded. "Yes, sir. It's said to be quite mild in its effects."

"And your intent is to compound the guilt factor by combining the Guilt Charm with an Incremental Accentuation Spell, hypothetically inducing paranoia?" Flitwick's eyebrows were practically dancing a tango as he tried to envision the result of this particular combination of magical spells.

"Yes, sir," Harry replied enthusiastically, his head bobbing in eagerness. He just HAD to sell Flitwick on this prospectus… "My idea is that the Guilt Charm is designed to affect the subject psychologically when there already exists something concrete for him to feel guilty about. Like when a child forgets to take the kitchen scraps out to the rubbish bin after supper. Or if a person does something wrong, such as lying, cheating, stealing, and so on. But to go beyond the concrete, I want to use an Accentuation Spell. If it works, the subject would experience a more abstract paranoia – feelings of guilt and fear without any discernible basis."

Harry's stomach tightened as he watched Flitwick's face. The tiny professor wore a peculiar expression, sort of a combination of cautious intrigue and disapproval, slowly nodding even as he frowned deeply.

"And the Incremental component of the Accentuation Spell?"

Harry bit his lip. "Well, I was thinking about the Accentuation increasing every six hours, to induce a constantly-growing sense of paranoia throughout the duration of the haunting experience. The Haunting Charm as a whole would be chronologically delimited to seventy-two hours."

"Three days," Flitwick mused, tapping his fingertip lightly upon the parchment before him, considering.

"Yes, sir." Harry grinned engagingly. "I was hoping to cast it upon Professor Snape on the evening of October 28. With the Delimitation set for seventy-two hours, the Haunting Charm should break of its own accord during the Halloween Feast."

"Ah," said Flitwick, his face clearing at last. "I take it that your project will act as a bit of a Halloween prank, eh, Mr. Potter? Drive Severus a bit batty, as it were, leading up to Halloween?"

Harry nodded brightly. "That's it exactly, Professor. IF I can get it to work properly. It combines three different elements, which answers the requirements of your Multi-Element Charm assignment. The Guilt/Compulsion Charm, the Incremental Accentuation Spell, and the Chronological Delimitation factor. I just hope I can manage to combine them successfully. If I do, and it works as planned, the perpetually-increasing baseless paranoia should produce a sense of feeling 'haunted' in the subject. In Professor Snape, that is."

Flitwick poised his quill over Harry's prospectus, peering intently at Harry from under his eyebrows. "And the Haunting Charm will terminate automatically during the Halloween Feast?" he verified.

"That's exactly what I'm planning, Professor. You'll be able to ask Professor Snape yourself if he'd experienced anything – unusual – during the past three days."

The Charms Professor's mouth quirked. "This is a highly ambitious project, Potter. My one concern is whether you can get it all to work in just one month's time before Halloween. You would still have the option of 'haunting' Professor Snape just before the term ends at Christmas, if you find that you require additional time to perfect your Haunting Charm."

"Thank you, sir," said Harry, smiling gratefully at Flitwick. "I appreciate your offer. But I'm still going to try for Halloween. Somehow, it seems more appropriate to haunt someone at Halloween than at Christmas!"

"I quite agree," chuckled Flitwick, dipping the quill into his inkpot and writing "APPROVED" on Harry's detailed prospectus. After drying the ink, the professor waved his wand to duplicate the prospectus, then handed the copy to Harry. "I'm always available to answer questions, Potter. If you need to experiment, please alert me in advance so I can be present in case something was to go awry."

"Yes, sir! Thank you, sir!" Harry beamed as he rolled up his copy of the prospectus and hurried away to Gryffindor Tower.

-:- -:- -:-

-:- -:- -:-