Severus Snape knew that today would be the day. Perhaps it was his new phoenix abilities, perhaps it was simply common sense and extrapolation from the events of previous Halloweens, but he knew- somehow- that today would be the day that the war ended, for better or worse. If he would survive it, or what would happen after, Severus could only guess.

The day had been surprisingly calm, for a Halloween, but Severus knew that it wouldn't last, not if his worries came to fruition, and, indeed, even his seventh years were rather jittery that morning and early afternoon, and, though he had planned a test, he ended up giving his various classes a practical, instead, wanting to instill at least some knowledge of defensive magic in their heads, in case they had to fight that day.

It was his last class of the day, a Ravenclaw-Slytherin class in the late afternoon, when the attack that he had been expecting all day was confirmed by a panicked voice in his head while he was trying to teach a lesson on dementors.

"PROFESSOR!" Potter shouted into his mind, making his skull ring with his intensity. Oh, Merlin, that was not a good sign.

"What is it, Harry?" he asked.

"Pansy Parkinson let in a bunch of Death Eaters and dark creatures via. the vanishing cabinet in the Rooms of Requirement! Please tell Dumbledore; we're hiding from them in the secret passageway behind the portrait of Harald Hardrada and the manticore right now."

"WHAT?!" Severus was furious, and rightly so. He thought he had taught his little snakes better than that; where had he gone so wrong?

"Yes; we've alerted the DA- that's the Defense study group I led last year- but there were no Slytherins or staff who know about that, so you'll have to warn the Light-side snakes and the teachers." Harry hastily responded. Good. So at least one of his students hadn't gone off his head, although Severus was willing to bet that it had been Granger who had remembered the enchanted galleon. Still, never mind about that now, pointless speculation would not get anything done, and he needed to warn the headmaster.

"Very well," he responded, already raising his wand to summon his patronus; Albus had to know about the invasion as soon as possible. "Stay safe, defend yourself, and don't lose your head. I'm going to mute the link so that we don't distract one-another."

"'Kay," was Harry's response, and then the link was muted on his side as well, and Severus could focus fully again. He shook his head to shake off the last haze of Harry's emotions, and then cast "Expecto littera patroni!" At once, his golden doe exploded from the tip of his wand and stood at attention, as his class stared at him, evidently assuming that this was a demonstration. The stares changed to looks of confusion and fear as Severus charmed it to carry a message, instead, and then sent it, with the message of: "We need aurors and the Order over here now, no time to lose, Parkinson let Death Eaters and allies into the castle" to Alastair Moody.

The doe bounded away, and Severus at once turned back to his students. "Right," he said, fixing them with a serious look. "The school is being attacked; class dismissed. If you are able and willing to fight, we need all the help we can get; otherwise it would be best if you could work in the infirmary or collect the lower years and keep them in the common room so they don't try to get involved in the battle."

The students appeared rather shell-shocked at the transmission of this intelligence. "But-" broke in one Ravenclaw.

"NOW!"

Said Ravenclaw squeaked and grabbed her textbook and wand, following the rest of the nearly-panicking students, and Severus allowed himself a moment to occlude before hastily leaving to secure the Slytherin common room and warn the rest of the teachers.

He was running faster than he ever had in his life through the dungeons now, feet nearly leaving the ground entirely in his haste. If Parkinson had let in a posse of Death Eaters, then the Dark Lord would be coming close behind, and his Slytherins- indeed, all the students- would be in grave danger. At last, he came to a stop in front of the bare stone wall which concealed the entrance to the common room. "Felix Felicis," he told it hastily, and then stepped through the opening created into the common room itself, startling all the Slytherins there.

"Professor Snape?" asked one of them, Pucey, if he remembered rightly. "What's wrong?"

"Hogwarts is being attacked by Death Eaters, and probably the Dark Lord himself," he responded. "I need the prefects to do a head-count and report everyone who is missing. Everyone under third year must either stay in the common room or help in the infirmary; if you feel as though you can't fight or have family fighting, stay and defend the first years or help in the infirmary. If you join the opposite side, you will be stunned and dealt with after the battle, if the more zealous Light side fighters don't attack you first, so I suggest staying neutral if you are not going to fight for Hogwarts."

The slightly shell-shocked Slytherins began organizing themselves into groups- some fighters, some field medics, some lower years, and some neutrals- at his (and the prefects') directions. One, Theodore Nott, foolishly cast a confringo at Severus himself as he turned to leave, but Millicent Bulstrode stunned him before Severus could even turn around, earning herself several automatic house points as Severus left in a hurry, trusting the prefects he had chosen, Greengrass and Malfoy, to keep the peace. And then he was heading for Dumbledore's office.

Severus had been trying to avoid Dumbledore all month. Ever since the Unspeakables had revealed his and Potter's secrets, Dumbledore had, like the meddling old man that he was, been trying to get more information and talk to Severus every spare minute. While some of his concern was certainly valid, considering that he was Headmaster of Hogwarts and thus had to ensure that Harry wasn't being harmed, it was still frustrating to be dragged into his office for lemon drops and a chat every time he had just settled down to do a bit of experimental brewing, and Severus had taken to brewing for the hospital wing overtime in the evenings, at least when he was not working on his lesson plans. But now was no time either for brewing or for chats.

"Bacon breath mints," he told the gargoyle, whose stone face seemed to look just as disgusted with the password as he felt, though it slid aside obediently. Severus stepped into Dumbledore's office at once.

"Severus! To what do I owe the pleasure-"

"To the fact that Pansy Parkinson just let about forty Death Eaters, Dark sympathizers, and some dark creatures into Hogwarts using the vanishing cabinet connecting Borgin and Burkes to the Rooms of Requirement."

The twinkle in his mentor's eyes died away immediately. "I see."

"I put the remainder of my Slytherins in lockdown," Severus continued, "and Potter and his friends are mobilizing the Gryffindors and the members of Potter's defense club; the other heads of house will have to be alerted at once."

"Yes, of course, excellent work, Severus."

Severus warmed inwardly at the praise, but he only nodded and left at a run to collect the rest of the teachers.

It took only a few minutes for Filius and Pomona to put the Ravenclaws and Hufflepuffs into lockdown, at least the ones who were too young or unwilling to fight, and then a lightening quick staff meeting had all of the teachers either running to protect their respective houses or heading for the seventh floor, to try to stop the Death Eaters and secure the Room of Requirements before any more Death Eaters came out. Septima and Bathsheba secured the wards of Hogwarts, with Dumbledore's help, while the others fanned out, each using their respective skill sets. Sweet Merlin, the things Minerva could do with Transfiguration! But Severus was not, as a matter of fact, paying much attention at all to the other professors, except when they needed help or one of them got in his line of sight. He was too busy blasting Death Eaters.

He had to admit it was surprisingly cathartic. He had had to pretend that he enjoyed being one of Voldemort's "elite" for so long, had to pretend that these depraved men were truly his friends, or as close to friends as partners in a terrorist organization could be, had to brew poisons that killed in terrible pain, and had to play along with the Dark Lords depravities...but now he was where he truly should have been, all along, fighting on the side of the Light with the rest of the professors at his side.

"Traitor!" roared McNair, and he whirled around, ducking just in time to miss a nasty gouging curse to the head. He responded with a clean sectemsembra and stepped over the body, only to see one of his Slytherins, Lillian Moon, being backed up against the wall by Goyle and Rookwood. Severus spat a curse, and the two wheeled.

They snarled the obligatory insults (well, at least Goyle did) before Rookwood fell to a stunner and Jugson to an "incendio", and Severus went on, almost intoxicated by the heat of battle, flinging curses and fighting off Death Eaters and defending his students with all the strength he had in him, while also attempting to keep an eye out for Nagini.

But that was when the next wave of the Dark Lord's creature allies began flooding into the hall.

Vampires came, fangs glinting as they attacked and attempted to turn the students, dangerous in their near-invincibility, despite the fact that a wizard-turned-vampire can usually no longer cast spells. Severus staked a few, then, seeing some of the Ravenclaw students blasting them with tanning charms, did the same, considering that it was certainly the easiest way to destroy them. He would have to remember to give Chang and Edgecombe points if he survived. And if they did, although he would sacrifice his own life if it meant he could protect his students (although, being a Slytherin, that would certainly be a last resort).

The vampires were followed by werewolves, Greyback's clan, and Severus couldn't help but shudder a little, although he would never have admitted it had someone commented. Werewolves were his least favorite dark creatures, despite the fact that they were only dangerous once a month; he had never stopped having nightmares of Lupin's slavering jaws even now, when he was a mind mage and able to somewhat control his dreams, and just the brush with death (or with ruination, had he been bitten) was enough to make his wand-hand falter. But he recovered himself within the instant, occluded harshly, and attacked at once, as the werewolves, dressed in muggle black leather jackets and spiked collars (for those who could afford such, like Greyback's favorites) or otherwise in rags, and bearing stolen wands, came at them.

There were trolls, dragons in great iron chains, inferi, and even giants, and though Severus fought his hardest, with all the skill of his double DADA mastery and Potions mastery, teachers and students and Order members were falling, and Severus could only cast the quickest of healing charms and portkey them hastily to the infirmary, sometimes without even checking to see if they were still alive. And still, the dark forces were coming, nor could Severus see either Nagini or her master. And why weren't the aurors here?!

It was at that time that the first dementor floated into the Great Hall, and Severus froze in horror. What if one of his students had been Kissed in the Halls? How had the foul creatures even got past the new wards that Dumbledore and the heads of houses had installed? But there was no more time for idle speculation now, not when the total despair fomented by the creatures was washing over the ranks of Light and Dark alike, causing them all to cower and lose their nerve, reliving all their worst nightmares.

"Expecto Patronum!" he barked, and his doe- Lily's doe- burst from his wand, glowing so bright it illuminated his face in it's pale glare, and made the students and teachers who hadn't seen it before gasp in shock. The Death Eaters, too, were frozen, and Severus managed to stun several before they regained their senses, all while the patronus was tearing up dementor after dementor, making the loathsome creatures flee as fast as they could float, only to be corralled toward's Harry's golden stag and annihilated, torn into bits of slimy black fabric and the white glow of souls being released.

And that was when Severus caught sight of the Dark Lord himself, shoving his way though followers and enemies alike as he stormed towards Potter, ruby eyes glowing from within with pure unadulterated rage. It was not a pretty sight. Severus attempted to approach, wanting to ensure that Potter was safe, but before he got more than a few steps from his place by the head table, Headmaster Dumbledore engaged the Dark Lord in combat, and Severus went back to defending his students, always keeping one eye out for the Dark Lord's last horcrux.

The tide of battle was beginning to turn. Despite the ever-replenishing dark forces, the Light seemed now to be beginning to hold their own, and Death Eater after Death Eater began to fall, while, too, did the dark creatures who had thrown in their lot with the self-styled Dark Lord.

Severus caught sight of Neville Longbottom facing off Bellatrix Lestrange herself, defiantly pointing her wand in his face. Worried about the self-conscious Gryffindor, especially considering what Lestrange had done to his parents previously, Severus weaved though several knots of fighters, ready to help, but as he approached, Longbottom waved him away shakily.

"Oh, does the wittle baby think he can duel?" Bellatrix taunted, twirling her wand like a baton. "Maybe if you're lucky you'll get a matching bed in St. Mungo's with your parents when I'm done with you!"

"The hell I will!" Longbottom spat in response, pale and shaking with anger and fear, and before Severus could do more than blink at the shyest boy in the school telling off his parents' attacker, Longbottom had cast a cutting curse which blinded one of Bellatrix's mad black eyes and tore across her beautiful features, ruining them irreparably. Longbottom followed that with a volley of curses and (for some odd reason) a jar of stinksap, before the screaming and half-blinded witch cast a lopsided incendio and fled, leaving Longbottom panting on the ground, staring after her fleeing form with eyes that overflowed with agonized tears. Even with his limited medical expertise, Severus knew that it was likely nothing short of phoenix magic could make Longbottom's burnt arm usable again.

Severus hastily approached the boy, handing him a portkey to the hospital wing (though he tried feebly to protest- something about leaving Hannah Abbot behind) and then resumed scanning the field for students in below their depth, sensing that that would be where his skills could be best applied.

Filius Flitwick took down the Carrows, one after the other, with an ingenious combination of glacial transfiguration and aquamenti charms, freezing them into twin lumps of ice before crumpling back against the wall, having been hit by a misdirected exviscera; Severus portkeyed him to the hospital at once, after pulsing a little phoenix magic into him to keep the disembowelment curse from causing any true damage.

Severus was beginning to lose count of all the Death Eaters he had to fight, of all the dead that he had to step over. He caught sight of Astoria Greengrass, eyes blank, and hoped against hope that she was still alive, despite recognizing only too well how a dead body looks. Macmillan, Boot, and Corner appeared to be down as well, though the bodies were not unmixed with those of the Death Eaters and sympathizers who had likewise been killed. All the while, the youthful version of Dumbledore dueled Voldemort, seemingly oblivious to the students falling around him. Severus took a breathless instant to grieve, before spotting Lavender Brown being smashed up against a wall by Jugson. He attempted to fight his way closer, but as he did so, Gibbon, Dolohov, Crabbe Sr, and Nott attacked him at the same time, and he could only hope that she would be able to fight off her assailant.

"You're lucky you lasted this long, Severus," Dolohov hissed, raising his wand. The other three were boxing him in by now, and though Severus stood tall, he knew there was a great likelihood that he would not survive.

"And you're lucky you haven't yet been caught by the aurors," Severus replied evenly, shooting off a quick confringo. Dolohov dodged, and suddenly all of them were casting at once and it was all he could do just to keep up a shield charm. He was struck by more than one crucitus at once, but, just as his vision began to grey around the edges, a girlish voice rang out, and Dolohov promptly turned into a large, goat-like animal, with crinkled horns and purple eyes on stalks. The other Death Eaters whirled around, but as they did so, three more jets of colored light exploded in their faces, and all three of them promptly crumpled to the ground, one dead, one covered in foot-long hair, and one whose head and bottom seemed to have reversed. Severus sat up, panting, to see Miss Lovegood, wand firmly in hand.

"Are you ok, sir? The flishtins told me that you were in trouble."

Severus took a moment to digest that before responding: "fine, thank you Miss Lovegood." He paused, but then could not resist asking "May I ask what spells you used?"

"Oh, tintinabulo, avada kedavra, crescere comas, and verto," she replied, without being perturbed that she had just admitted to using an unforgivable and two unknown spells. Severus might have made a response to that, but at that instant, he caught sight of Harry, fighting Nagini with a wave of fiendfyre that made both sides of the conflict stare and Severus sigh, and then the snake was whipping around on the floor of the Great Hall, smoking, charred coils writhing, a horrible scream mingling with her agonized hissing, and then, at last, Severus knew that the Dark Lord's last horcrux was gone. He also knew that Voldemort would be far from happy about that.

He was right. Voldemort's scream of pain, fear and rage was inhuman, as he was, a cry of pure bestiality. He stood for a moment as if unable to believe that his beloved pet and horcrux was dead, and then he lunged for Harry though the mailström that was the Battle of Hogwarts, his accidental magic flaring out to knock Headmaster Dumbledore flat on his back and making all of the candles in the Great Hall flare up like mini tongues of fiendfyre.

And then he and Harry were dueling, and the rest of the combatants left off fighting to watch the magnificent duel. It was fast, passionate, and charged with so much magic that it literally flowed off of both of them in a churning whirlwind of black smog and blue phoenix fire, both of them casting dark and light magic indiscriminately. It would be considered, in later years, a duel to go down in history, the second leading duel in a battle which would have its own chapter in Hogwarts, a History. Severus, however, could only think of how ill-matched it was. For all his training, for all his powers, for all the phoenix magic which all who knew the prophecy knew was "the Power the Dark Lord knows not", Harry was still only sixteen years old to Voldemort's seventy-one, and he was, in addition, already tired from fighting and healing other students, while Voldemort had only dueled Dumbledore, and (while that was no small feat) he had much more endurance. Before long, Harry was bleeding in multiple places as his formidable phoenix magic shields were worn though, and yet Voldmort continued to attack him. Severus got the horrible sense that he was only toying with him, only trying to use him as an object lesson to his followers and all the others watching. And that was when the Dark Lord finally tired of the sport, and cast the killing curse.

He couldn't breathe. Harry couldn't die- he was too young, he had a whole life in front of him, he had a prophecy to fulfill! Severus didn't even stop to think; he would later say that if he had, he would not have done something so blatantly Gryffindor. But as it was, he lunged forward, dark robes whipping around him, and caught the green light on his broad chest. And the world dissolved into blazing waves of silver fire, falling away around him.