Severus came to him in pieces. Like the horcruxes he would discover in the years to come, the young man's life in service to Voldemort had cost him the integrity of his soul. Grief had blasted through the fractures and fissures that already existed, rending his spirit apart. Only a disparate jumble of fragments remained by the time he returned to the Headmaster's office, slumped in the high-backed guest seat like a discarded rag doll.

Albus had sifted through the rubble, jagged edges nicking his fingers until he had found the one he wanted; the infant Harry, the last remaining trace of the woman Lily Potter. He had wielded this cutting truth like a scalpel, extracting a promise from Severus. Now came the extraordinary task of rehabilitating the dangerous young wizard, of piecing together his sundered soul.

He began by setting the wounds in a firm cast of expectations and demands. There was scarcely a month left before the start of term, so he gave Severus two weeks to be consumed by grief. After that it was clear that he would be treated as any other junior staff member; that is to say, worked to his very bones. But this first stage of healing was a tricky thing; expose the wounds too soon and they would never heal properly, let them fester too long and the infection would only spread. The first night, or whatever was left of it once their tearful parley had ceased, Severus had remained in that same stiff chair as if he were chained to it. I shouldn't be alone, he had croaked, and Albus had understood. Better here among the portraits' accusing glares than sequestered in the dungeons, where poisons, knives, and bad memories neatly lined the dusty shelves, eager to be put to use. Left to himself, it could well have been his last night on earth - and the last thing Hogwarts needed was another vengeful ghost. Albus had woken to the sight of a gorgeous sunrise painted across the young man's blotchy, stricken face. The painted heavens shone, wholly ignorant of the darkness that swelled inside him.

He had been taken down to the dungeons through a secret passage used only by the elves (and, no doubt, a few of the evening ladies of Hogsmeade in days long past) and shown to his chambers before any visitors were allowed in to see the Headmaster. Albus prided himself on his discretion. Though the young wizard would never have known it, Albus kept a close watch over him, and the house-elves were never far away. His two weeks of solitude were volatile as a fever, and Albus watched with quiet sympathy as he cursed and cut and burned away his pain. He would rage through the day at the not-so-deaf stone walls, his Philippics reaching only the Headmaster's ears and the disinterested elves, who still viewed him with unspoken disdain. At night his anger would ebb into misery, and he would weep like a wound, spilling tears and bile until he lapsed into a fitful sleep.

At last, sleep began to come to the young man in more regular intervals, and some nourishment made its way into his belly without being cast abruptly back up again. Albus noted this with satisfaction; it was a sign that the healing would soon begin. A sign he remembered from his own days of grief and anguish. He had been so young then, full of hubris and ambition. Like Severus, the scythe of death had cut him down with its indifferent, irreversible swing.

He had given himself much more time then. He had spent years wandering the dark forests of his soul, roaming the wasteland where his love once grew wild and lush. He had searched for a cure for his broken heart, a nugget of wisdom to explain the meaning of death. But in the end, he knew now, the process was always the same. Stepping out of the shadows, forging unbearable pain into a new, fragile kind of hope - it was just as difficult after a decade as after a fortnight.

Besides, he reasoned, the start of term would soon be upon them. There was no one else to teach Potions. Albus was a kind-hearted wizard, but he was nothing if not practical.

On the last day of his self-imposed exile, Albus had dismissed the house-elves and ventured down into the dungeons himself. He had pushed open the leaden door to the Slytherin Head of House's private chambers and glided through the mess of soiled handkerchiefs, dirty clothes and broken things. The unwashed stench of depression clung to every surface like the decayed contents of a raided tomb.

Severus had been sitting in the same spot where Albus had espied him upon leaving his office; he was hunched over the edge of the bed, his face half-obscured by shadow. However sure Albus was that he was still flesh and bone, Severus looked like a corn husk doll, brittle and lifeless. A single match and he'd have burned like parchment; one blow and he'd have crumbled into dust.

I'm not ready, he had mumbled from behind his filthy hair. It's too soon... Albus had reached out a hand and the young man had pulled himself up, swaying like a drunk, like a kid on its first hooves. There had been such fear in his eyes that Albus had had to grit his teeth to keep his chin from trembling.

The children need you, Severus, he had said, placing the young wizard's wand back into his hand for the first time since that fateful night. And, he had added, after a long and difficult pause, I need you, too.

With those words the first ray of sun had pierced through the room's tiny, barred window, and in the fertile ashes of Severus' grief, something began to grow. Albus' eyes sparkled as he strode away to his other duties, dewy and hopeful as the morning outside.