14 June 1997

Severus fingered his wand and stared at the blank wall of his office, his black eyes unblinking.

The headmaster had not yet returned from his excursion. Where exactly he had gone…well, Severus was not privy to that knowledge. After all, Dumbledore did not like to place all his secrets in one basket—particularly one that spent so much of its time dangling on the arm of the Dark Lord, Severus recalled bitterly. Never mind that Severus carried the deepest secret of all: that the headmaster did not intend to survive the school year—which meant that Severus's promise, his duty, his vow loomed inescapably on the horizon…

"Don't kill me!"

"That was not my intention."

Clenching his jaw, Severus rose to his feet and glided slowly down the dark dungeon room. To raise his wand against Dumbledore was a fearsome thought…and yet, it had become unavoidable—his destiny—his purpose, in a long chain of predetermined events—Dumbledore's perfect plan. Dumbledore was simply one in a number of links that anchored Severus to life. And when those links were all severed, when his purpose had been served…well, it seemed clear to Severus that he was not meant to survive to discover how the rest of the plan would play out. No, his purpose was very specific; that much was evident.

"Well, Severus? What message does Lord Voldemort have for me?"

"No—no message—I'm here on my own account! I—I come with a warning—no, a request—please—"

Severus turned around and faced his office. If it were to happen tonight, would he ever see this office again? Would he ever again sit at his desk and grade students' papers? Menial work, and he had always hated it…but to leave Hogwarts, the only place on Earth he had ever truly been able to call home…it would render a ringing finality.

Suddenly, there was a loud scuffle outside Severus's office door. Severus whirled around, drawing his wand. Two voices—no, three—could be heard. With a jolt, Severus recognized Granger's unmistakable, know-it-all simper—and then, Lovegood's ethereal intonation—

BANG.

Severus's office door flew open and Filius stumbled inside, his eyes wide with fear. Severus drew himself to his full height, holding his breath.

"Severus! Death Eaters! In the castle! Minerva asked me to fetch you—the Order of the Phoenix—they're fighting—the Astronomy Tower—the Dark Mark—"

"What request could a Death Eater make of me?"

"The—the prophecy…the prediction…Trelawney…"

Severus's mind went blank. Death Eaters, in the castle—Draco had somehow managed to elude the Order's watchful eye. A sudden image of Draco with his trembling wand trained on Dumbledore flashed across Severus's eyes, and suddenly, the path forward was clear: he had to act alone—and fast.

Without even a moment's hesitation, Severus raised his wand and slashed it through the air. With a blinding flash of red light, Filius keeled over and fell forward, unconscious. Ignoring the pounding of his heart against his ribcage, Severus strode down the office and swung open the door.

"Ah, yes. How much did you relay to Lord Voldemort?"

"Everything—everything I heard! That is why—it is for that reason—he thinks it means Lily Evans!"

The dungeon hallway felt darker than usual. His peripheral vision had disappeared—his mind felt like a maze. Severus walked forward without conscious thought. Dimly, he was aware of sending Granger and Lovegood into his office to tend to Flitwick. Vaguely, he was aware of hearing his office door shut and Granger's muffled gasp of horror. A strange mantra was playing in his head…an old memory, an old conversation…

"The prophecy did not refer to a woman. It spoke of a boy born at the end of July—"

"You know what I mean! He thinks it means her son, he is going to hunt her down—kill them all—"

Severus's legs seemed to be moving forward of their own accord, as he swept up the marble staircase to the seventh floor. He could hear the noises in the distance—the bangs, and the screams—the cries of terror—oh, but none of them knew that Severus had yet to deliver the final blow. Severus's heart began fluttering in earnest. Quickening his pace, he continued down the hallway, his black robes billowing behind him.

"If she means so much to you, surely Lord Voldemort will spare her? Could you not ask for mercy for the mother, in exchange for the son?"

"I have—I have asked him—"

"Severus!" Lupin's voice sounded miles away, even as Severus walked right past him. "Severus, they're at the top of the tower! We can't—we can't get through! They've blocked the stairs—Reducto! REDUCTO!"

Ignoring Lupin, Severus swept down the remainder of the corridor. Faces, hexes, flashes of light flew past him in quick succession—Minerva twirling and slashing her wand; Longbottom struggling to get up from the floor; the Weasley girl and Tonks engaged in a deadly duel with Rowle, who was mindlessly casting curses in every imaginable direction; Gibbon lying on the floor, dead…

"You disgust me."

Severus marched through the invisible barrier, and felt the telltale tingle of his Dark Mark—the foul key to the impenetrable lock.

"You do not care, then, about the deaths of her husband and child? They can die, as long as you have what you want?"

The trek to the top of the tower seemed to last an eternity. It could have been a year that Severus was climbing up the tower stairs, his footsteps echoing in a kind of a sick drumroll. His heart seemed to be intent on leaping out of his throat, now.

"Hide them all, then. Keep her—them—safe. Please."

The door to the ramparts loomed ahead of him. Squaring his shoulders and swallowing the jittery anticipation that had risen in the back of his mouth like bile, Severus stepped forward and slammed the door open, his breath catching in his throat as he took in the scene.

Yaxley, Greyback, and the idiotic Carrows were standing in a semicircle around Draco, whose face was paler and whiter than the sliver of moon in the sky. And slumped against the battlements, his entire body limp, his head rolling backwards, but his gaze as piercing and calm as ever, was Dumbledore.

Black eyes met blue, and suddenly, no one else in the room mattered. It was just the two of them.

"And what will you give me in return, Severus?"

"We've got a problem, Snape," Amycus's voice was mere background noise. "The boy doesn't seem able—"

"Severus…"

Severus stepped forward and shoved Draco out of the way. Dumbledore's voice was like a trigger. The moment, he knew, was seconds away.

"In—in return?"

Severus twitched his wand in his hand and gazed at Dumbledore, the last man to trust him, to even attempt to understand him. The last man on Earth who didn't think him a coward. Dumbledore could call it whatever he wished, but murder was murder and dead was dead. Severus lifted his chin, feeling nothing but self-hatred and revulsion.

"Severus…please…"

"Anything."

"Avada Kedavra!"