Slowly, the ghost began to coalesce out of shadows and air, darkening to an appearance of solidity. She had seen him in the courtyard first, just past James’s shoulder—for a moment she had thought he was Jesse, and nearly panicked.

But Jesse could not appear during the day. Most ghosts took no notice of sunrise or sunset, though, and this one was no exception. He did appear to be a young man, but looked nothing like Jesse: he was sandy-haired and short, with a sharp, pointed face. He wore the clothing of the Regency era—breeches and boots and a wide cravat, like a portrait of Mr. Darcy. There was a desperate look about him as he drifted a little closer to her, twisting his insubstantial top hat between his hands. “Miss Herondale,” he said, his voice a low whisper. “I have heard that you listen to the dead. That you can help us.”

There was a rattling sound: more carriages, arriving in the courtyard. Lucie shook her head slowly. “I can see and hear the dead,” she said. “But I do not know what I could do to help you. I don’t think I’ve ever been very helpful in the past.”

The ghost’s eyes were entirely colorless. He blinked at her. “That is not what I’ve heard.”

“Well,” said Lucie, “I cannot help what you’ve heard.” She started to move away. “I ought to go inside.”

The ghost held up a transparent hand. “I can tell you that the ghost of the young lady whose body lies in the courtyard has already awakened,” he said. “She is filled with the grief and terror of the newly dead.”

Lucie sucked in a breath. Not all the dead became ghosts, of course. Only those who had unfinished business in the land of the living. “Filomena? She—she didn’t pass on?”

“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….”

“Enough!” There were tears on Lucie’s face. “I will do it,” she said. It’s all right, she told herself. If I can speak to Filomena’s shade, perhaps she can tell me who murdered her. It will be worth it. “I will do it. I will make you forget.”

The ghost let out a long sigh—a sigh without breath; it sounded for all the world like wind through broken boughs. “Thank you.”

“But first,” she said, “tell me where Filomena is.”

They found their way to the library. The world was swaying around James like the rolling deck of a ship. He staggered over to a long table and braced his hands on it; he was dimly aware of Matthew beside him, of Cordelia’s soft voice as she spoke to Anna. He wanted to go over and put his head in Cordelia’s lap. He imagined her stroking his hair, and pushed the image away: he already owed her an apology for earlier that morning.

Memories of his dream were pouring into his mind like water through a smashed dam. London streets—light glinting off a blade. Red blood, red as roses. The recollection of a song, sung in delicate Italian, verses turned into screams.

And that hatred again. That hate he could not fathom or explain.

“Math,” he said, rigid with strain. “Tell—Anna. Explain to her.”

Voices swirled around James, Anna’s calm and measured, Matthew’s urgent. Thomas and Cordelia chiming in. I have to get hold of myself, James thought.

“Daisy,” he said. “Constantinople.”

“Oh God, he’s raving,” said Thomas dismally. “Perhaps we ought to get Aunt Charlotte—”

“He’s not,” said Cordelia. “He’s just having an awful time—Thomas, do move out of the way.” James felt her cool hand on his shoulder. Heard her soft voice as she bent toward him. “James, just listen for a moment. Focus on my voice. Can you do that?”

He nodded, grinding his teeth. The hatred was like knives in his skull. He could see hands scrabbling at cobblestones, feel a sick sort of pleasure that was the worst bit of all.

“Once Constantinople was called Basileousa, the Queen of Cities,” Cordelia said, in a voice so low he suspected only he could hear it. “The city had a golden gate, used only for the return of emperors. No one else could pass through it. Did you know the Byzantines created Greek fire? It could burn underwater. Mundane historians have lost the source of the fire, the method of its making, but some Shadowhunters believe it to have been heavenly fire itself. Imagine the light of angels, burning beneath the blue waters of the Stamboul port….”

James closed his eyes. Against the back of his eyelids, he could see the city take shape—the minarets flung darkly against a blue sky, the silver river. Cordelia’s voice, low and familiar, rose above the clamor of his nightmare. He followed it out of the darkness, like Theseus following the length of thread out of the Minotaur’s labyrinth.

And it was not the first time. Her voice had lifted him out of fever, once, had been his light in shadows….