“She screams, but she is alone,” said the ghost. “She cries out, but none can hear.”

“But I ought to be able to hear her,” Lucie cried. She turned back toward the courtyard—spun in a circle, looking about wildly. “Where is she?”

“She barely knows,” the ghost whispered. “But I know. And she remembers. She remembers who did this to her.”

Lucie narrowed her eyes. “So take me to her, then.”

“I will not. Not unless you do something for me.”

Lucie put her hands on her hips. “Truly? Blackmail? You’re a blackmailing ghost?”

“Nothing so untoward as that.” The soft-spoken ghost lowered his voice even further, in a way that made the hair on the back of Lucie’s neck rise. “I have heard that you can command the dead, Miss Herondale. That threescore of the Thames’s drowned souls rose at your bidding.”

“I should not have done it.” Lucie felt a little sick. She could still remember that night, the ghosts rising from the river, wearing the uniforms of prisoners, one carrying Cordelia in his arms. “I could command you to leave me alone, you know.”

“Then you will never know where the girl’s ghost is,” the ghost said. “And it is only a small thing I want from you. So very small.” In his urgency he had grown more solid. Lucie could see that he wore a stylish fawn-colored jacket, and that the lapel of the jacket was pocked with charred black holes. Bullet holes. She was reminded suddenly of the ghost of Emmanuel Gast, a warlock who had appeared to her after his murder, covered in blood and viscera. This at least seemed to have been a cleaner death. “You would have my consent, and also my gratitude, if only you would command me to forget.”

“Forget what?”

“The reason that I cannot rest,” he said. “I murdered my brother. I spilled his blood in a duel. Command me to forget my last sight of his face.” His voice rose. “Command me to forget what I have done.”

Lucie had to remind herself: no one could hear the ghost but her. Still, she was shivering. The force of grief around him was almost palpable. “Don’t you see? Even if you did forget, that wouldn’t free you. You’d still be a ghost. And you would not even know why.”

“It matters not,” the ghost said, and his face had changed. Behind every ghost’s face, it seemed to Lucie, there lay the mask of death, the shadow of the skull beneath the phantom skin. “It would be better. What I endure now is torment. I see his face, every waking moment I see his face, and I can never sleep.…”