Livvy went in first, laying the quilt on the bed. Ty set the cardboard box on the floor, then wandered over to where Mark was lying. He picked up the quilt that Livvy had set down and knelt beside his brother. A little awkwardly, he laid the quilt on top of Mark.

Mark jerked upright. His blue-gold eyes flew open and he caught hold of Ty, who gave a sharp frightened cry like the cry of a seabird. Mark moved with incredible speed, flinging Ty to the ground. Livvy screamed and darted from the room, just as Cristina hurtled inside.

Mark was kneeling over Tiberius, pinning him to the ground with his knees. “Who are you?” Mark was saying. “What were you doing?”

“I’m your brother! I’m Tiberius!” Ty was wriggling madly, his headphones sliding off to hit the floor. “I was giving you a blanket!”

“Liar!” Mark was breathing hard. “My brother Ty is a little boy! He’s a child, my baby brother, my—”

The door rattled behind Cristina. Livvy burst back into the room, her brown hair flying. “Let him go!” A seraph blade appeared in her hand, already beginning to glow. She spoke to Mark through gritted teeth, as if she’d never met him. As if she hadn’t been carrying a patchwork quilt for him through the Institute only moments before. “If you hurt Tiberius, I’ll kill you. I don’t care if you’re Mark, I’ll kill you.”

Mark stilled. Ty was still writhing and twisting, but Mark had stopped moving entirely. Slowly, he turned his head toward his sister. “Livia?”

Livvy gasped and began to sob. Julian would be proud, though, Cristina thought: She was weeping without moving, the blade still steady in her hand.

Ty took advantage of Mark’s distraction to hit at him, connecting solidly with Mark’s shoulder. Mark winced and rolled away without striking back. Ty leaped to his feet and darted across the room to join Livvy; they stood shoulder to shoulder staring at their brother with wide eyes.

“Both of you, go,” Cristina said to them. She could feel the panic and worry rolling off them in waves; Mark could clearly feel it too. He was wincing, opening and closing his hands as if in pain. She bent down to whisper to the twins. “He’s frightened. He didn’t mean it.”

Livvy nodded and sheathed her blade. She took Ty’s hand and said something to him in the quiet, private language they had. He followed her out of the room, pausing only briefly to look back at Mark, his expression hurt and bewildered.

Mark was sitting up, panting, his body bent over his knees. He was bleeding from the reopened cut on his shoulder, staining his shirt. Cristina began to back slowly out of the bedroom.

Mark’s body tensed. “Please don’t go,” he said.

Cristina stared. As far as she knew, this was the first coherent thing he’d said since arriving at the Institute.

He lifted his chin, and for a brief moment she saw beneath the dirt, the bruises, and the scratches, the Mark Blackthorn she had seen pictures of, the Mark Blackthorn who could be related to Livvy and Julian and Ty. “I’m thirsty,” he said. There was something rusty, almost disused, about his voice, like an old motor starting up again. “Is there water?”

“Of course.” Cristina fumbled a glass off the dresser and went into the small attached bathroom. When she emerged and handed the full glass to Mark, he was sitting up, his back against the footboard of the bed. He looked at the glass wryly. “Water from taps,” he said. “I’d almost forgotten.” He took a long swallow and wiped his mouth with the back of his hand. “Do you know who I am?”

“You’re Mark,” she said. “Mark Blackthorn.”

There was a long pause before he nodded, almost imperceptibly. “No one has called me that in a long time.”

“It’s still your name.”

“Who are you?” he said. “I should remember, probably, but—”

“I’m Cristina Mendoza Rosales,” she said. “There is no reason you should remember me, since we have never met before.”

“That’s a relief.”

Cristina was surprised. “Is it?”

“If you don’t know me and I don’t know you, then you won’t have any—expectations.” He looked suddenly exhausted. “Of who I am or what I’m like. I could be anyone to you.”

“Earlier,” Cristina said. “On the bed. Were you sleeping or pretending?”

“Does it matter?” he said, and Cristina couldn’t help thinking that it was a most faerielike reply, a reply that didn’t actually answer her question. He shifted against the footboard. “Why are you in the Institute?”

Cristina knelt down, putting her head on a level with Mark’s. She smoothed her skirt over her knees—even when she didn’t want them to, her mother’s words about how an off-duty Shadowhunter must always be neat and presentable echoed in her head.

“I am eighteen,” she said. “I was assigned to study the ways of the Los Angeles Institute as part of my travel year. How old are you?”

This time Mark’s hesitation went on for so long, Cristina wondered if he was going to speak at all. “I don’t know,” he said finally. “I was gone—I thought I was gone—a long time. Julian was twelve. The others were babies. Ten and eight and two. Tavvy was two.”

“For them it has been five years,” Cristina said. “Five years without you.”

“Helen,” Mark said. “Julian. Tiberius. Livia. Drusilla. Octavian. Every night I counted out their names among the stars, so I would not forget. Are they all living?”

“Yes, all of them, though Helen is not here—she is married and lives with her wife.”

“Then they are living, and happy together? I am glad. I had heard the news of her wedding in Faerie, though it seems long ago now.”

“Yes.” Cristina studied Mark’s face. Angles, planes, sharpness, that curve at the top of his ear that spoke of faerie blood. “You have missed a great deal.”

“You think I don’t know that?” Heat boiled up in his voice, mixed with bewilderment. “I don’t know how old I am. I don’t recognize my own sisters and brothers. I don’t know why I’m here.”

“You do,” said Cristina. “You were there when the faerie convoy was speaking to Arthur in the Sanctuary.”

He tilted his face toward hers. There was a scar across the side of his neck, not the mark of a vanished rune, but a raised welt. His hair was untidy and looked as if it had been uncut for months, years even. The curling white tips touched his shoulders. “Do you trust them? The faeries?”

Cristina shook her head.

“Good.” He looked away from her. “You shouldn’t.” He reached for the cardboard box that Ty had left on the floor and pulled it toward him. “What is this?”

“Things they thought you might want,” Cristina said. “Your brothers and sisters.”

“Gifts of welcome,” said Mark in a puzzled tone, and knelt down by the box, removing a hodgepodge of odd items—some T-shirts and jeans that were probably Julian’s, a microscope, bread and butter, a handful of desert wildflowers from the garden behind the Institute.

Mark raised his head to look at Cristina. His eyes glittered with unshed tears. His shirt was thin and ragged; she could see through the material, see other welts and scars on his skin. “What do I say to them?”