Lucie brushed her palms down the skirt of her dress, leaving black smears of dust. “I raised the ghost of a warlock before I came here. Emmanuel Gast. Your mother might have mentioned him.” Grace said nothing; undeterred, Lucie plowed on. “He placed the protection spells on your brother when he was born. He said he’d left an anchor in him. In his soul. I think it was—was an opening for a demon to get in and possess him.”

There was no sound. No response from Grace. Only her harsh breathing.

“Jesse is not like other ghosts. He is awake at night,” said Lucie. “During the day, he sleeps, or something like it. His ghost vanishes when the sun rises. He doesn’t remember those hours. All the murders have taken place at dawn, when Jesse would be unconscious, unaware of what his body is doing. Unaware that he was being possessed and controlled.”

Grace’s lips trembled. “You’re saying he’s the killer,” she said. “That a demon is using his body. Making him murder people. Shadowhunters.”

“Not just any demon—”

“I know,” said Grace. “You mean Belial.”

The single word rocked Lucie back against the wall. “You know? What do you know?”

“Months ago, when you came here—when I realized you could see Jesse,” said Grace. “There was a demon here. My mother had arranged for it to be sent, to threaten me. To demand I do what she wanted.” Her voice was leaden. “Do you remember what it said to you?”

Lucie nodded slowly. “ ‘I know you. You are the second one.’ ”

“I thought at first it meant only: the second Herondale,” said Grace. “But I began to suspect more. I went through my mother’s private papers. I had always known she dealt with demons, some very powerful indeed. But that was where I saw his name, and I understood. Belial. You are the second of his grandchildren.”

“Does James know?” Lucie whispered. “About your mother, working with Belial?”

Grace shook her head. “I never wanted him to,” she said. “After all, what else do my mother and Belial have in common but a hatred of your family? My mother hates so blindly she could tell herself there was no danger in tying herself to a Prince of Hell. But I never thought—” Her voice shook. “I thought there was one thing she cared about. Jesse.”

“She may know nothing about this,” said Lucie, a little reluctantly. She hardly wanted to defend Tatiana. “She hired Gast to put the protection spells on Jesse because she hates the Silent Brothers, not because of Belial. She may not even know Belial had left an opening there, a way for him to return and to possess Jesse.”