Disclaimer: I don't own Harry Potter and Co. They are the property of J. K. Rowling.

Some lines of dialogue are taken directly from "Snape's Worst Memory" in OotP and "The Prince's Tale" in DH.

Thanks: To Lola Little, my lovely beta reader.

A/N: This story covers the 1975/76 school year. Leaps in time are denoted by '- - -' between sections. '- - - Initials - - -' indicates narrator point-of-view.

Warning: This work is rated M for a reason! It deals with themes of violence, sexuality, rape, and suicidal thought. Reader discretion is advised.

Commutability

Chapter 1

"This life is filled with hurt. When happiness doesn't work, trust me and take my hand. When the lights go out, you will understand..."

--Three Days Grace, "Pain"

- - - SS - - -

Severus Snape stared at the pale hand extended to him. It was a sight that should have filled him with joy. Instead, his stomach knotted violently. The 15-year-old desperately tried to quash the sensation--now was not the time for nausea. Not when he was seated before the Lord Lucius Malfoy. And certainly not when said lord was fast becoming impatient as his hand hung unanswered in the air.

"I'll be there," Snape said and hastily took that hand. Two firm pumps, and that was that. Offer made. Offer accepted.

In two months' time, Severus Snape would be a Death Eater.

"Excellent," Malfoy drawled, smoothly exchanging Snape's hand for a snifter of brandy. "To the future, then." He smiled briefly, indulgently, and Severus' gut clenched again. That expression belonged on the face of some doting grandparent, not on the 21-year-old chief recruiter for the Dark Lord Voldemort.

"To the future, " Snape managed to echo, raising his glass.

Malfoy's smile widened. Then he knocked back his 25-galleon cognac like a 10-sickle shot, slammed the delicate stemware down on the table, and abruptly rose. He casually straightened his acromantula silk robe and gestured imperiously for Severus to follow. After a half-second staring wistfully at the alcohol he'd planned to nurse for the next half-hour, Snape stood, wincing slightly as his second-hand robe rubbed against his sore shoulder, and trailed Malfoy out of the Hog's Head Tavern.

The pub door closed behind them with a dull thud, and suddenly the world exploded in light and sound and laughter. Vendors lauded the merits of their wares. Housewives haggled and grinned at the open-air stands. Through the doors of more permanent establishments floated strains of music from the Wizarding Wireless. Above the play of guitars, drums, and bagpipes, students shouted and teased and generally cheered their free weekend in the well-worn comfort of Hogsmeade village. Malfoy sneered, "Uncultured swine."

He turned back to Snape, affected a smile just a bit too wide to pass for benign, and said, "'Til the Solstice, then."

The youth nodded mutely, inchoate alarm once again roiling in his belly.

With one last smile that was more of a smirk, Lucius turned and apparated away. Severus stared after him for a long moment, then turned as well and began the long, lonely trudge up to Hogwarts School of Witchcraft and Wizardry.

Snape could, of course, have waited for his friends and taken a thestral-drawn carriage up to the castle, but he wanted to be alone with his mixed feelings and the weight of the life-changing decision he'd just made and-- Snape tripped on a pothole and cursed!

A fall that normally would have wounded only pride ripped open barely healed gashes along the back of Severus' shoulder, and he bit his lip hard to keep from moaning as he regained his feet. He grimaced at the feel of warm blood sliding down his spine and dampening his shirt. Then he firmed his mouth into a thin, hard line. The pain, Snape decided, was a good thing. It grounded him physically when emotionally, he had felt adrift on the currents of uncertainly. How stupid to doubt young Lord Malfoy because of a few strange looks when right on his back was all the proof Severus needed that supposedly 'good' and 'noble' people were nothing but frauds!

Severus violently kicked a loose rock and winced, then did it again. Yes, the youth confirmed, the pain was a good thing, unlike the good deed that had led to his injury. The thought flickered through his mind and he knew the saying was true: 'No good deed goes unpunished.'

- - -

Snape's good deed occurred at 10:32 on Wednesday, September 3rd. Professor Horace Slughorn caught Severus on his way out the classroom door and asked the boy to tutor a student. Snape, in a hurry to get to Transfiguration, agreed. It was nothing new or special, after all. One housemate or another was always looking to barter goods or services for homework answers. It was a bit odd that this plea for help should come through Professor Slughorn, though. Most Slytherins quickly discovered their Head of House was more interested in what they could do for him than vice versa. But the term had just started, and many 11-year-olds, even ones wearing green and silver, still looked at adults with blind trust.

The idea that the child in question might not be a new Slytherin never crossed Severus' mind. The other houses treated Snape like a walking case of Dragon Pox. The only non-Slytherin who treated him like a human instead of a disease was Lily Evans, Severus' childhood neighbor. The redhead had been his best friend since they were both 9, but the girl hadn't once contacted him since her family moved to Surrey at the beginning of the summer.

Thus, when Remus Lupin sat himself down at Snape's library table that night, the Slytherin's first thought was that Evans had sent her housemate along with a message saying she either missed him desperately or decided he wasn't worth her time after all. His second thought was that the first was ludicrous. Lily had never been shy about confrontations. She never needed a giggling entourage of friends to pass notes for her. And even if she had, Evans certainly wouldn't have chosen Lupin, the silent partner in a quartet of bullies--the self-dubbed 'Marauders'--to do the job.

So, by way of greeting, Severus spat, "What the hell do you think you're doing here?"

"I-I'm here for my lesson," Remus sputtered. "Every Wednesday and Saturday, was what Professor Slughorn said..."

The lights went on for Snape, and his stomach seized. "You are my tutee."

"Well, yes," Lupin said, bemused. "Why else would I be here?"

Severus could think of a dozen reasons--all utterly wretched but still preferable to the truth. Indeed, the truth was utterly unbearable. What kind of Slytherin blindly agreed to help some nameless student? What happened to his guile, his cunning, the paranoia that came from four long years of harassment? Snape cursed himself for a fool. While he was at it, he cursed his mother, too; for while his muggle father's name meant nothing in the wizarding world, Severus' mother was born a Prince, and Princes always kept their word.

A sudden movement from the shelves drew Snape from his self-censure and diverted his ire back outward. There, lurking in the shadows, were Sirius Black, James Potter, and Peter Pettigrew. "Why else, indeed?" Severus asked.

Remus followed his gaze and had the good grace to blush. "I-- It's not-- They're just here so you don't hex me!"

"I was informed I would be tutoring a student in Potions tonight, not engaging in a formal duel. You'll notice I don't even have a second, while you have a third and forth. However, if you'd prefer to forfeit my services..."

Lupin was up in a second, exchanging heated whispers with his friends and pointing toward the exit. The three shot warning glares at Snape, and Black added a two-finger salute. Severus returned it with relish and watched the trio stomp out of the library under Madame Pince's disapproving gaze. He would have preferred for Lupin to bail, but irritating Black almost made up for it.

"Sorry about that," Remus apologized, retaking his seat at the table. "Like I said, they meant the best."

Severus just managed to check his sneer of disbelief. Lupin seemed entirely too keen on having Snape for a tutor; so if he was to be stuck with the boy, Severus supposed he should at least make an attempt at civility.

"And I want you to know I really appreciate--"

"Take out your quill and parchment, Lupin, and stop prattling. This is a Potions tutorial, not a platform for elocution," Snape interrupted. Maybe civility was a bit too big a step.

"I-I'm sorry, Severus. I didn't--"

"I didn't give you permission to use my forename, Lupin. Now, take out your quill and parchment."

Frowning dejectedly, Remus did so.

The following weeks continued in much the same vein. Severus attempted (unsuccessfully) to maintain the cool, polite tone he used with his Slytherins, and Lupin behaved as if he had ingested a Babbling Beverage. The routine was quickly wearing Snape's paper thin patience to transparency, and the continued presence of Sirius Black behind the bookshelves did not help matters. Inversely, Remus seemed to be developing a resistance to Severus' biting sarcasm and frequent dismissal of any sort of gray matter between the temples. In fact, the brunette acted as if the clearly forced urbanity was a heartfelt offer of friendship. It made Snape want to retch.

So, when Black handed him a note one Friday toward the end of the month--a note from Lupin declaring that the boy wanted to meet with him 'under the moonlight' instead of at the library the next day--Severus knew it was high time to set the other boy straight. It was bad enough that he had to listen to Black's Slytherin cousin, Narcissa, go on and on about how the recently graduated Lucius Malfoy was 'playing hard-to-get,' when everyone knew her intended simply loathed her. Snape had no desire to be on the receiving end of a similar romance, least of all with another boy.

Crumpling the letter in a white-knuckled fist, Severus marched directly up to the portrait entrance of Gryffindor Tower (which Lily had pointed out to him 'in case he ever needed to talk'). Evans had probably meant 'in case he ever needed to talk to her,' but, well, that was why one learned to be precise in one's speech. The devil was in the details. Snape demanded that the Fat Lady either let him in or bring out Lupin, who had 'coincidentally' skipped class that day. So much for Gryffindor courage.

It was James Potter who finally answered the door with a Bat-Bogey Hex, which Severus handily deflected. Potter frowned in disappointment and asked, "What do you want, Snivellus?"

"To see Lupin," Snape replied, voice dripping with distain, "about our meeting tomorrow."

Something flickered in Potter's hazel eyes before he stepped fully into the doorway, blocking it with a body considerably sturdier than Severus' own. "He's a bit under the weather at present. Feels as rotten as you look, I'd say. So, kindly bugger off."

With a parting Furnunculus and a snide comment that Potter should see to his own boil-covered countenance before worrying about another's, Snape pivoted on his heel and left, school robes billowing behind him.

- - -

Severus Snape had inherited many of his father's worst characteristics: the hooked nose, the oily hair, and, of course, the long-lived temper. That temper, quick to ignite and slow to fade, led Severus to actually follow the note's instructions on the 20th of September, 1975. If Remus Lupin felt the need to be disabused of his too-friendly notions at certain time and place, the Slytherin would do so--without mercy.

Thus, Severus abandoned his usual nighttime study spot and stole through the halls toward the front doors. All the while, he cursed Lupin, who was too 'ill' with nerves to confront Snape like a man. He cursed Potter, whose quidditch-trained muscles forced him to wait to deal with this. He cursed Pettigrew, who had likely encouraged the whole thing, the simpering wretch. But most of all, he cursed Black, who should have done them both a favor and never delivered that blasted note.

Severus slid out onto the grounds, glad that the full moon at least made things easy to navigate, and slunk around to the Whomping Willow. The teen levitated a broken branch to punch a knot at the base of the tree, which instantly stilled, just as the letter said it would. He ducked into the cramped, dirt tunnel hidden there. It was as damp and dim and cold as the dungeons in the old stone castle, but a great deal filthier. How terribly enchanting for a first date, Snape thought sarcastically.

"Lumos," he murmured.

Severus trudged through the twisting corridor until he finally found the trap door behind which Lupin was no doubt hiding. He flung it open with a snarl to find Remus waiting--stark naked. He looked anything but seductive, though.

The boy screamed. He gurgled. He wept. Bones snapped and skin boiled as Lupin writhed and twisted on stained, wooden floorboards, body flopping like a fish out of water through slats of moonlight.

And then suddenly it was all over.

One second, two, passed. Then two amber eyes snapped around to focus on Snape, who instinctively took a step back toward the door he had just come through.

"Oh," Severus breathed, "oh Merlin." His analytical mind took in the details in a split-second: thick bristles of light brown fur, upright ears, a tufted tale, four legs instead of two, and of course, those eyes that gleamed with all the malice Lupin in human form never showed.

"You're a werewolf."

As if it had been waiting for the human to figure that out, the beast drew back its gums in a hideous smile and lunged.

Snape dove back into the tunnel. The light at the end of his wand faltered. The world went dark, and in that darkness every sound was magnified: the sudden pounding of blood in ears, the scuff of dirt underneath skidding trainers, the thwump of paws on hard-packed earth, the inhuman howl of rage and hunger, two sets of panting lungs, and the keening "oh-Merlin-oh-Merlin-oh-Merlin" between shouts of "Stupefy! Homorphus! Quit dodging, damn it!"

And then the rip of fabric! The squelch of skin and fat and muscle and blood! The shrikt of claw on bone--on scapula and ribs! A scream torn from a throat! A howl of victory! A new voice shouting "Snape!?"

Footsteps! Hoofbeats! Heartbeats! A yelp!

Silence.

"Snape? Snape? Can you hear me?"

"...Potter?"

"Come on. We gotta get out of here."

Severus was hefted to his feet. Agony blossomed across his back as deep claw-tracks were ripped open even further, but he managed to only hiss in pain. "Did you kill it?"

"No. Come on." Potter moved with practiced ease through the twining tunnels, an arm on Snape's elbow to lead him. The lack of a Lumos betrayed that James knew these tunnels, that he was part of this set-up.

"If you wanted to kill me, why did you stop it?"

"I would never want-- Sirius-- We gotta get out of here."

The exit was deftly found; the willow, easily stilled. The moonlight blinded Severus after the pitch blackness underground, and the pristine stillness of the lawn and lake seemed to mock the boy after the horror he had just experienced. He supposed he should feel lucky that he could still appreciate the irony with a human mind, that he his back had been shredded but not bitten into, and that he was not a werewolf now himself. But he couldn't quite feel anything, and as he followed Potter back to the castle proper, Snape wondered if he was in shock.

A harried-looking Professor McGonagall met them at the school doors. "Thank Merlin, you're back," she said, and Severus wondered if she wasn't speaking more to James than him. He wondered how the woman had known they were gone in the first place. Was she in on this too? But that couldn't be right. The professor was stern, but she wasn't cruel--was she?

"Follow," McGonagall said tersely, and Potter automatically obeyed, dragging the still dazed Snape by the elbow. Severus recovered enough of himself to shake the arm free, but a few hallways later, his steps began to waver. Potter cast him a look that was part annoyance and part worry. He ruffled his hair nervously, then jogged the few steps to McGonagall's side.

"Professor," James said, darting his eyes exaggeratedly toward the lagging, pale-faced boy behind them.

McGonagall whirled around, misinterpreted the look, and snapped, "Mr. Snape, I believe I said, 'Follow.'" She caught the elbow James had only recently dropped and dragged Severus forward. He bit back a cry at the rough treatment, and noted absently that the entire back of his shirt felt quite soaked with what could only be his blood. He wondered if he'd bleed out before either of his two escorts noticed.

"I don't know what you thought you were doing out after curfew," the teacher continued, "but I will not wait about while you think up your excuses. The Headmaster wishes to see you all now."

"'All'?" Potter queried.

"Yes, all," she replied. "You may have reported the infraction, but the professors at this school are hardly blind."

Severus repressed the impudent urge to laugh as the woman pulled him, heedless of his mauled back, toward the stone gargoyle that guarded the entrance to the Headmaster's tower.

"You two and Misters Black, Lupin, and Pettigrew are like ants. Where there is one, the others are never far. And as Mr. Lupin is currently... indisposed..."

She knew, Snape thought. That was not the wording of someone who learned a half hour ago that her pupil was a ravenous monster. She knew there was a werewolf in the school and never once warned the other students.

"I had Mr. Filch collect your cohorts before coming after you myself," she finished. "Licorice wands."

The gargoyle leapt aside, and McGonagall led the way up the moving staircase toward Dumbledore's office. Severus' stomach twisted, though whether at the jarring motion or the prospect of facing the man behind the oak door at the top (who must have known about Lupin, too), he wasn't quite sure. The professor knocked and was bid to enter.

"Headmaster," she greeted.

"Minerva," the old man replied gravely, rising to meet her. "Boys. Please take a seat." He gestured toward a set of spindly chairs in front of his massive desk. Two of them were already occupied.

"Misters Pettigrew, Black," McGonagall acknowledged. Peter and Sirius beamed at their Head of House, but a disapproving glare had them slapping on contrite expressions. Severus nearly groaned at how convincing they looked; he wondered if he should even try to defend himself to Dumbledore or if they had already poisoned the man against him.

"I trust you can deal with this lot, Headmaster?"

"Of course, Minerva. Thank you."

The tartan-clad woman bowed out of the room, and to Severus, the soft click of the latch sliding home in the jamb after her seemed like the clang of a prison door.

The Headmaster sat back down in his overstuffed, over-patterned seat and gazed, one by one, at the four pupils before him. "Well," he finally said, "would you care to explain what happened here tonight?"

Severus met the older man's solemn blue gaze with a challenging black. "They tried to kill me, sir, with the werewolf you're hiding here."

There were angry squawks of denial from the other boys, but Dumbledore calmly ignored the barb. "That's a very serious charge, my boy. I know you all have something of a history, but you seem in remarkably good health for an attempted murder."

Snape narrowed his eyes. His back was beginning to stick to the cushioned chair he was in. "I wasn't bitten, if that's what you mean."

"That is good news," Dumbledore said, cheering noticeably. "But I am most intrigued as to how you discovered your classmate's unfortunate affliction."

"Snivellus was just sticking his great greasy nose where it didn't belong!" Sirius exclaimed. "Following poor Remy out there to do Merlin knows what! Probably chop him up for potion parts, the slime-ball!"

"Now, now, Mr. Black, name-calling is hardly becoming," the headmaster chided.

"B-But he's right, Headmaster," Peter piped up, watery eyes darting briefly to Snape. "Remus only ever tried to be friends with that snake--"

"Mr. Pettigrew," Dumbledore admonished.

"Th-that Slytherin, I mean!" Peter squeaked. "But Sniv--Snape was up to something! Always eyeing our Remy! So--So if Sirius wrote him that note, it's his own fault for following it like some pervert! Sirius is perfectly innocent!"

Black glared daggers at his cohort, who flushed bright red when he realized he'd just implicated his friend instead of exonerating him. Hope flared in Snape's heart at the mistake.

James shot Severus an almost apologetic look, then jumped to his housemate's defense, saying, "Really, Headmaster, you know Sirius. He may leap before he looks, but he's not malicious. He was just out for a laugh."

"'Out for a laugh'? 'Not malicious'?" Snape sneered. "Are we talking about the same Sirius Black?

"Headmaster, Black forged a note changing where I meet Lupin to study. If luring someone to where a vicious monster is waiting to eat or infect you isn't malicious, I don't know what is."

"Siri didn't mean--" James began.

"He gave me the letter a full day in advance, so it could hardly be argued that this plot was unmeditated," Snape spat.

"P-plot!?" Pettigrew cried. "It wasn't like-- We weren't all--"

Black shot the twitchy boy a scathing glance that shut him up mid-bluster.

Severus raised an eyebrow and turned back to the Headmaster. "Sir, Lupin may be only an accessory here, but Black at least"--Severus hardly believed the other two Gryffindors were innocent, but Peter's accidental intimations and James' comments in the tunnel pinned Sirius as the mastermind--"deserves expulsion. Possibly a hearing before the Wizengamot, sir."

"Hm," the Headmaster said. His bushy eyebrows drew together in thought as the accused made puppy dog eyes at the man who'd always favored him.

Finally, Dumbledore nodded his shaggy white head and announced, "I believe what we have here is a prank gone horribly wrong."

"A prank!?" Severus choked.

"Yes, Mr. Snape, a prank. One in very poor taste, but still just a prank. I think you overestimate both Mr. Black's propensity for true evil and his ability to think about the consequences of his actions, even given a fairly lengthy period to think about them. Thus, I will be deducting 50 points, Sirius."

"Fifty points!" Sirius moaned. James elbowed his housemate in the ribs, and the boy quickly adopted a penitent look.

Dumbledore nodded gravely, then brightened. "I believe there are also some points to award, though. Mr. Potter has shown what good can come from the noble heart combined with a rather rash Gryffindor's mind. For your rescue of Mr. Snape--at risk to your own life and limb--James, I'll be awarding you 50 points."

"Fifty points?" James beamed. Peter and Sirius grinned broadly at him.

Emboldened by the gain, Pettigrew squeaked, "And Sniv-- Snape, sir?"

"Ah, normally I would be forced to dock points from Slytherin for breaking curfew, but I believe the fright he's had will discourage such misbehavior for the foreseeable future. Wouldn't you agree, my boy?"

Severus nodded mutely, unable to form words through his rage.

"Now, straight back to the dorms, the three of you. Mr. Snape and I have a few more things to discuss before we call it an evening."

Chairs scraped, and the door opened and closed.

"Severus, my boy--"

"I'm not your boy," Snape interrupted, somewhat surprised at how level his voice sounded when inside, he felt as mangled as his back.

Dumbledore frowned, looking as if he truly had no idea that a gross miscarriage of justice had just occurred. "I know this must be very difficult for you. It's not everyday one discovers a friend is not what you thought he was."

"That thing is not and never has been my friend."

Dumbledore sighed.

"You're a very smart boy, Severus, but a little compassion might do you good.

"That 'thing' is a boy very much not in control of his circumstances. A boy just as much a victim in this as you are. I must insist you give your Word to keep silent about his condition. It's a very delicate situation, and I should hate to see the ministry called in for a near miss.

"And I'll need you to continue tutoring poor Remus, as well. It would raise suspicions..."

No. No! It had to be a joke. Secrecy was one thing, but this! If ever there were a situation calling for the negation of a partnership, near-cannibalism would be it! But the Headmaster's blue eyes were not twinkling in jest.

"If you will, then?"

Severus forced his jaw to unclench. "On my honor as a scion of the House of Prince--"

"Ah, no. Your Word, Severus."

Of course. The old man wanted more than an oath; he wanted Snape's Word as a Wizard, a magical binding just a step short of an Unbreakable Vow! It rendered the maker mute instead of dead if broken, but to a young wizard only beginning to experiment in nonverbal casting, it was potentially devastating. Severus told himself he shouldn't be surprised. If one ugly, unhappy Slytherin's life was only worth fifty house points--and not even that, once you factored in Potter's reward for chickening out on murder--why on earth should his mother's traditionally Slytherin bloodline count for anything more? Severus seethed inside but aloud intoned stoically, "I, Severus Snape, solemnly swear to make good on my word: to tell no man--"

"Or woman," Dumbledore cut in, leveling a sharp eye at the lad. "Or to write it."

"--Or woman, in speech or in writing, that Remis Lupin is a werewolf."

"So worded. So witnessed," the Headmaster said and aimed his wand. "So shall it be." A tongue of magical flame leapt forward to wrap itself around Snape's throat. It seared his skin, sank into his flesh, and left an angry red collar for half a second before that too faded out of sight, leaving the boy gasping but unscarred.

"And?" the old man asked expectantly.

Severus fought to control his breathing. "I... Severus Snape... solemnly swear to make good on my word: to demand no end to Remus Lupin's tutelage this year--"

"School year."

"--Of our schooling, though by right, I should be able to."

Dumbledore frowned, but nodded. "So worded. So witnessed. So shall it be." Once again spell-fire settled across the teen's vocal chords.

"If... that's... all?" the boy panted.

"Yes, Severus, it is. Thank you. Now I dare say you could do with a warm bath and a good night's rest."

Snape was too winded to even sneer at the man. He stood, wavered, and caught himself on the back of the seat he'd just vacated. Turning to leave the office, Severus felt... numb. He couldn't even take a twisted delight in the Headmaster's gasp of shock at finally fully seeing the boy's shredded back and the dark red stains on his chair. Snape couldn't gather up the energy to be angry that even the color of his blood betrayed him to Gryffindor.

"Severus! Mr. Snape!" Dumbledore called in alarm, but Snape ignored it. The old man had already made his opinion of the youth crystal clear. To be appraised at so little, held in such low regard that he had to be magically silenced while bleeding out... He pushed past the office door, stumbled down the spiral staircase, and skidded out into the main hallway. By the time he made it down the last few stairs to the dungeons, Severus' vision was swimming, and his brain was treading water.

Fifty points. The thought floated tauntingly at the surface of Snape's mind. Fifty fucking points from the golden Gryffindors for conspiracy to commit murder. You'd lose as much for seriously cheeking McGonagall.

Fifty points gross, but a net loss of zero. Because he was just a Slytherin. And just a Snape. And the most he could hope for was to serve the intended instrument of his demise and continue those damnable lessons with Lupin.

Severus watched the bit of wall that hid the entrance to the Slytherin dorms tilt alarmingly right, then left, as if the very foundations of the school were no more stable than the sea. "Sextans," he muttered wearily, feeling unmoored instead of helmed by the password. The wall slid open, and Snape staggered inside. In the pale, green light of the common room, he was sure he looked just as sick as he felt. It was late, though, and no one was up to tell Severus he was right. He staggered into fifth-year boys' bedroom.

The absolute normalcy of Adrian Wilkes' snores slammed over Snape like a tsunami, washing away the last of his self-restraint, and he let out a short, soft sob. Tears began to prick at the boy's eyes as he fell into bed, thinking he was more likely to die there than merely sleep--and no one would care. For the first time since Black had dubbed him 'Snivellus' in first year, Severus let the threatening tears fall, and unconsciousness claimed him.

- - -

Severus woke late the next day, surprised to be alive.

Then he noticed the half-empty vials of Blood-Replenishing Potion and Dreamless Sleep on his bedside table. Closer inspection revealed the labels to be commercial, and thus not from the small, self-brewed pharmacy Snape kept locked in his trunk. The note beside the bottles confirmed Severus' suspicions about the potions' origins.

'Snape, you prat,' it began in Michael Mulciber's nearly illegible script.

'I hope you're happy. I had to save your bleeding (literally) life with my personal potion supply--and you know how much Mother already bitches about keeping me stocked for quidditch. You'll be brewing me a bottle of each of BRP and DS to replace the ones you will no doubt finish once you wake (whenever that may be), plus an extra batch for my troubles. It's hard work forcing potions down an unconscious person's throat, you know.

'Much put upon,

'Mulciber.

'P.S. What the hell happened? Those wounds wouldn't respond to direct magic at all. They'll scar spectacularly!

'P.P.S. Next time you plan on battling whatever it was, take me with you! Binn's homework is bloody boring, and it must have been some show!'

Snape quickly downed the potions, ignoring his muscles' scream of protest at the movement, and thinking, just before blackness overtook him once more, how he would take one politic Slytherin over four supposedly noble Gryffindors any day.

- - -

When Severus next struggled back into consciousness, there was a new note on his nightstand.

'Snape, you prat,' this one said.

'Your absences in class this morning lost Slytherin a total of 50 points. Excessive, I know, even for McGonagall. She's usually a hard ass, but man, were her whiskers in a real knot today--probably run out of catnip, again. Do you think she laces her drink with the stuff? Anyway, I'm sure you can earn them all back. Old Slughorn offered points to "any enterprising students who feel the need for some advanced brewing in preparation for the OWLs." Like that's what anyone'll be brewing down there. Heh. Do try to drag yourself up for dinner, though. I'd hate to have your die after all my hard work.

'Duly concerned over our chance for the House Cup,

'Mulciber.'

Snape let out a sharp bark of laughter.

Fifty points. He had been unconscious for nearly two days after self-medicating for wounds that, due to the lupine nature of the classmate who inflicted them, could not be closed by magical means. And for this, they had taken points.

Severus felt ill again--acutely so--and stumbled to the loo.

He emptied what little was still left in his stomach, moaning softly as every heave agitated his scabbed back and shoulder. Then, Snape carefully washed his face, maneuvered into a clean Hogwarts robe, and gathered the books he'd need for Care of Magical Creatures. The sight of Narcissa Black holding court with the younger girls in the common room stopped Severus dead in his tracks. The young woman was going over some missive she'd received from her fiancé, somehow interpreting yet another of Lucius Malfoy's diatribes as some kind of coded love letter.

Lucius. Codes. Snape was struck by inspiration. He dropped his books and immediately made for the owlery. Narcissa looked up briefly, then shrugged, and went back to her wedding plans.

Crouching in the hay of the aviary, Severus inked his quill and began to write:

'Esteemed Lord Malfoy,

'I pray you forgive this unsolicited correspondence, but as you always availed yourself to younger students during your prefecture at this zoo they call a school, I hope writing you now is not too bold. I will cut straight to the point. I recently witnessed exactly how serpents are treated by the reputedly humane Albus Dumbledore, and the man is not fit to make change at the Magical Menagerie! As a housemate of your fiancé, I am often regaled with stories of your devotion to certain social causes, especially the proper care and treatment of magical creatures. As such, I understand that the proprietor of your favorite shelter, a fellow lord I believe, has a fondness for reptiles? If I may, I ask that you venture a proposition to him on my behalf--I have a snake in need of a home.

'Awaiting your kind response,

'Severus Snape.'

The answering scroll was dropped in Severus' breakfast by a striking eagle owl. After a quick Evanesco to rid the parchment of grease, the fifth-year read:

'Dear Mr. Snape,

'There is no need to apologize for your letter. I was glad to receive it, though understandably less glad about the circumstances that necessitated it. Please let your housemates (barring young Ms. Black, who takes too many liberties with my name and time as it is) know that I remain at their disposal, even though I am no longer in their dormitory. As for whatever tales Ms. Black has been spinning, keep in mind that there is no falser creature than one in heat; it will do anything to secure its mate. On this point, however, Ms. Black is correct: I am indeed a lover of oft overlooked animals, and it seems to me that your current zookeeper forgets he runs more than just a big cat enclosure. He has specialized in the care of mammals at the expense of his snakes, and frankly, it is a wonder he has yet to be bitten. The associate you referenced, however, is an experienced snake handler, and he is most anxious to see the creature you described in a better environment. As his representative in this matter, I believe it would be best to negotiate the terms of transfer face-to-face, where you could explain in detail the specific needs of this species. I understand there is a Hogsmeade outing next weekend. Perhaps we could meet then?

'Cordially yours,

'Lord Lucius Malfoy.'

Snape's reply was a grant total of three lines long: salutation, 'of course,' and signature.

- - -

The first Saturday of October dawned bright and clear, and if Severus had been the type to appreciate such things, he might have said it was one of the loveliest fall days he had ever seen. Snape was not that type, though, and even if he had been, he was far too busy dodging his roommates and Lily Evans to weather-watch. Snape was disgusted with the lot of them, Slytherins and Gryffindor alike, for he had managed to side-step the oath Dumbledore coerced from him by hinting (rather than stating directly) that docile little Lupin was a raging lycanthrope. In light of the upcoming holiday, though, his friends had taken it as a joke. Their pre-Halloween skepticism made Snape want nothing more than to sit and to stew in his alternating numbness and fury. It was, he decided, rather like potions. Boil for x amount of time. Allow no contaminates. Then add the correct catalyst...

Severus' catalyst awaited him at the entrance of the Hogs Head Tavern in Hogsmeade, and he resolutely followed the smiling Lord Malfoy away from the bright, crowded stores on High Street into the dark, dust-moted bar. Over glasses of x.o. cognac in surprisingly clean glasses, the two young men mused over the relative values of lions, birds, and badgers--with Snape dropping some speculation on wolves in the mix--before settling down to the matter at hand: the price of one serpent's soul.

In the end, it was sold rather cheaply and rather quickly. It was, Snape would decide later, a matter of context. Anything seems a fine offer compared to a pittance of house points.

So, when Lucius extended a hand and asked with a hungry smile, "You'll join us on Winter Solstice, then? It'll be a bit of Christmas come early," Severus could only take a fortifying gulp of brandy and remind himself that smile meant he was wanted.

"I'll be there," he answered and did his best to tamp down the foreboding that filled his stomach as the deal was sealed.