She moved as silently as the shadows that were her namesake through Dun Scaith, and even he often did not hear her until she was standing right at his shoulder, her eyes intent with the level gaze of a hunting wolf. She was nearly of a height with him—tall for a woman—and he found that that still surprised him, even after months living within her halls.

"Show me the Sword Feat," she would say without preamble, and he would draw his sword and toss it from hand to hand, flipping it, letting it arc over his head and turning to snatch it by the hilt before it struck the earth—glancing sideways at her for her approval. The most he ever received from her was a short nod, and then another command, running him through his paces: "Show me the Wheel Feat. Show me the Feat of the Spear's Reaching. Show me the Salmon Leap."

"I have been able to do the Salmon Leap since before I came to you," he protested.

"Show me anyway," she said, her eyes dark and her voice tolerant with the edges of her amusement, which was a dark and quiet thing.

"It proves nothing."

"Show me anyway." He opened his mouth, and she pre-empted him, one hand raised. He could see the bronze bracelet on her wrist—the only jewelry she wore in her own fortress—flash in the hall's fire light. "Because I wish you to," she said. "Or do you question me?"

"No, Master," he said, and changed his breathing, gathered the muscles of his body and showed her the salmon's leap, the high arching jump that stretched the muscles of his body to their fullest, the leap that in battle would carry him over the shields of his enemies and that now carried him high over the great fire of Dun Scaith, and he thought as he landed lightly on the balls of his feet that he saw a smile flicker quick as light on water across Scáthach's face.

He did not know how old she was. She looked no more than perhaps ten year his senior, but she had a daughter nearly grown, and the stories of her had gained the weight of legends. He thought perhaps she was not wholly human. He could believe easily that she was kin of the Morrigan. She had the dark hair and dark eye, the skin white as the promise of a gentle death.

And then there was the day she went out to meet her rival on the plains below Dun Scaith, to show her strength, to keep her name. He had trained with her through three summers and three winters, but she was ever careful with her students. "To put a warrior in battle before his time is like to put an ill-prepared pot in the kiln," she said. "You will shatter the pot, and perhaps also damage its neighbors." But he chafed, and hoped, and waited.

He had seen her spar many times, but he had never seen her prepare for true battle. In the hall of Dun Scaith, before the hearthfire, she shook her hair back over her shoulders and put on her torc, the one she never wore in her own chambers—the bronze torc whose ends were fashioned in the shape of the heads of ravens, the patterns of their wings becoming long twining knots on the torc's curve. She wore but little, in the fashion of both his people and her own, so that he could see the scars of her arms and her back. She held out the bowl of woad paint to him. "Hold this," she said.

"Do I come with you?" The thrill of bloodlust rose in him like a spring bubbling to the surface. "Will I fight?"

"In the fullness of time," she said. "Hold it steady for me." With quick motions, her eyes half-closed, she painted her face with whorls and dots of blue. Her fingers returned to the bowl, then trailed over her skin: again, again, again. Her skin was fair as ice, its only color borrowed from the firelight; the dark markings broke the pale expanse of her skin and made her all the more inhuman. Her black hair borrowed color from the fire, turning gold and red, more extravagant than a king's treasure. In that moment she was surely something more than human, and yet more real than one of the fair folk; he could have easily believed her a goddess.

"My back," she said, and she slid a hand under her hair and lifted it, so that he could see the curve of her neck and the arch of her spine between her shoulders, above the line of her leather armor. "Mark it for me. This one is easy: dip the tips of three of your fingers in the paint, and draw them from one shoulder to the other."

He did so. His hand was steady; it did not shake. Her skin was warm as the skin of any living woman. When she turned to look at him again, her eyes were again the eyes of wolves. "I believe you are ready," she said. "Prove yourself, Hound of Culann. Show me what I have taught you."

And there was blood, and frenzy, and the earth beneath his feet—the weight of his spear in his hand, and his bronze sword heavy, and he let his training rise up, so that he rose with the salmon leap, and struck, and whirled and struck again, and to his right and in front of him he could see Scáthach, pale as a star, dark as night, fighting with silent intensity against an opponent many times her size and far louder than her, but who was losing to her, falling beneath the flashing of her sword.

Scáthach, he thought in wonder, before the frenzy took him and he knew nothing in his vision but the red of blood.

"You fought well," she said after. From her, this was the highest praise possible. He felt as though the fire were burning beneath his skin, as though he had become drunk on mead, for all that he had not yet touched his cups. He was dizzy with the battle and its aftermath, dizzy with the smell of blood and earth and the crackle of fire, and she was shadow, cool and dark, even now: watching him.

"Master," he said. "What now?"

"Is your blade clean?" she asked. "Have you cleaned your spear of blood?"

"Of course," he said, stung that she would ask; it was the gravest insult to your weapon and to Brigid of the Smithy, to leave it to tarnish with the blood of your enemies. "I cleaned it as soon as the frenzy left me."

"Good," she said. "But your body is also a weapon. I have made it so. And you are muddied and fouled with blood." She lifted her chin a little. "Come with me."

He followed.

He had never seen her chambers. She had a great hearth, and a bed of furs, and—at this time, at her bidding—a basin of hot water, and wool cloths, laid out before the blazing fire. Steam rose from the water. She wet a cloth and gave it to him, and then wet another and began to clean her skin, to wash away the blue of woad, the red of blood. He took the cloth and did the same, carefully. He had not realized how much he was coated in dust until he had the chance to wipe it away.

"You have bloodied yourself in battle," she said. "You have come into your own, Hound of Culann—though I always preferred your birth-name, if the truth is told. Setanta."

"I have not been called that since I was a child," he said.

"And you are a child no longer, Hound of Culann. That is true." She let the last of her leather armor fall away, and ran the cloth down over her breasts and belly. Her skin, cleaned of blood and sweat and woad and still damp with water, gleamed white like strange gems in the light of her fire. He could not look away. "Do you desire me?" she asked; he did not know how to answer. She was beautiful; she fired his blood; she terrified him. "I asked a question," she said, after a moment, amused but not ungentle. "Answer yes or no without fear."

"Yes," he said, "Master."

"Then come," she said. She stepped away from the basin of steaming water, toward the furs that made her bed. It was said she hunted with the Hounds of the Hunt, and slept on the pelts of the beasts she caught in their company; but many things were said of Scáthach, and Cú Chulainn wondered for the first time how much was true and how much false, how much she was a goddess and how much a woman, and what the shadows of Scáthach contained. "The water is warm," she said, "but the night air will be cold. Come."

He went and joined her; he could not have done otherwise.

He was no innocent; he could not have been. But she had a depth of knowledge he could not match, and a strength that he could match; he felt as though she filled him and emptied him, relentless. There was no softness in her, except in the black cloak of her hair, loose around her shoulders and around him.

She stroked him, her hand rough, spear-callused, sword-callused, until he writhed helplessly among her furs and said, indignant, plaintive, "Master!" And she laughed, which sound he had never heard before: low and rich. And she said, "I forget: you are young. Then I will not make you wait." And she rose up on her knees and moved over him, and he caught her strong hands as she lowered herself onto him and . . .

. . . the Shadowy One moved slow and steady on him, and she was warm, real, a woman, and yet with a warrior's strength, and he knew why the stories tied her to the Morrigan or to the Hunter, because no one of his people or her own knew what to make of her: as they knew not what to make of him, the Hound of Culann, fated to a short life and a brilliant one. She was not a goddess and yet she was, for she held greatness in her hands where others could not even conceive it.

He thought of those things, until she arched her spine and flexed around him, and drove all thought from his mind.

And at the end, she bent her head so that her hair fell over her shoulders, black as night but touched with copper from the firelight, and he said, "Master!"—because she was, because she had taken the raw stuff of his strength and his frenzy and made of it an edged weapon, honed fine—and she did not cry out but sighed and shivered. And he closed his eyes and knew he made a noise, said something, but could not say what it was, because it was too much, and the only thing he knew was the warmth of her body and the sound of his own blood.

She slid off him smoothly, and rolled over to lay beside him, among the furs. They were both breathing hard, as after the battle. After a time, she began to speak.

"I will teach you the using of the Gae Bolga," she said, "and the Thunder Feat, with which you will be the terror of a nation, Setanta, and then you will be my student no more. I will have taught you everything I can. What remains after that is only the gaining of experience, and of sorrow. Sorrow and knowledge are close kin; that is the way of the world."

Battle and pleasure made him bold. He said, "Knowledge and joy can be close kin, too; I regret nothing of what you have taught me, Master."

She laughed again, the sound like the touch of furs against his body. "You will not call me that much longer, I think. I will miss it when you stop."

He smiled in the dark.