Malcolm grinned. It transformed his whole face. If Emma had still held lingering doubts about his guilt, about the story Kieran had told, they vanished in that moment. His mobile, amusing features seemed to harden. There was cruelty in that smile, framed against a backdrop of echoing, depthless loss.

A flare went up from the table, a burst of fire. Diana cried out and stumbled back, out of the circle of protection. It sealed itself up behind her. She hurled herself to her feet and threw herself toward Tavvy, but this time the circle held fast; she bounced off it as if off a glass wall, the force sending her staggering back.

“No human thing can cross that barrier,” said Malcolm. “I’m guessing you had a charm to get you through the first time, but it won’t work again. You should have stayed away.”

“You can’t possibly hope for success, Malcolm,” Diana gasped. She was clutching her left arm with her right; the skin looked burned. “If you kill a Shadowhunter, the Nephilim will hunt you for the rest of your days.”

“They hunted me two hundred years ago. They killed her,” said Malcolm, and the throb of emotion in his voice was something Emma had never heard before. “And we had done nothing. Nothing. I do not fear them, their unjust justice or unlawful laws.”

“I understand your pain, Malcolm,” Diana said carefully. “But—”

“Do you? Do you understand, Diana Wrayburn?” he snarled—then his voice softened. “Maybe you do. You have known the injustice and intolerance of the Clave. If only you hadn’t come here—it’s the Blackthorns I despise, not the Wrayburns. I always rather liked you.”

“You liked me because you thought I was too frightened of the Clave to look closely at you,” Diana said, turning away from him. “To suspect you.” For a moment she faced Emma and the others. She mouthed RUN at them silently, before turning back to Malcolm.

Emma didn’t budge, but she did hear a movement behind her. It was quiet; if she hadn’t been wearing a rune that sharpened her hearing, it would have been inaudible. To her surprise, the movement was Julian, disappearing from her side. Mark was next to him. Silently they slipped back into the tunnel.

Emma wanted to call after Julian—what was he doing?—but she couldn’t, not without alerting Malcolm. Malcolm was still moving toward Diana; in a moment he’d be where he could see them. She put a hand to the hilt of Cortana. Ty was gripping a knife, white-knuckled; Livvy held her saber, her face set and determined.

“Who told you?” Malcolm said. “Was it Rook? I didn’t think he’d guessed.” He tipped his head to the side. “No. You weren’t sure when you got here. You suspected . . .” His mouth turned down at the corners. “It was Catarina, wasn’t it?”

Diana stood with her feet apart, her head back. A warrior stance. “When the second line of the poem was deciphered and I heard the phrase ‘Blackthorn blood,’ I realized that we weren’t searching for a killer of mundanes and faeries. That this was about the Blackthorn family. And there is no one more likely to know about a grudge that goes back years than Catarina. I went to her.”

“And you couldn’t tell the Blackthorns where you went because of the reason you know Catarina,” said Malcolm. “She’s a nurse—a nurse to mundanes. How do you think I found out—?”

“She didn’t tell you about me, Malcolm,” snapped Diana. “She keeps secrets. What she told me about you was simply what she knew—that you’d loved a Nephilim girl and that she’d become an Iron Sister. She’d never questioned the story because as far as she knew, you’d never questioned the story. But once she told me that, I was able to check with the Iron Sisters. No Nephilim girl with that story had become one of them. And once I realized that was a lie, the rest began to come together. I remembered what Emma had told us about what she’d found here, the clothes, the candelabra. Catarina went to the Spiral Labyrinth and I came here—”

“So Catarina gave you the charm to get you through the protection circle,” said Malcolm. “Unfortunate that you wasted it. Did you have a plan or did you just rush here in a panic?”

Diana said nothing. Her face looked carved out of stone.

“Always have a plan,” said Malcolm. “I, for one, have been crafting my current plan for years. And now here you are, the proverbial fly in the ointment. I suppose there’s nothing to do but kill you, though I hadn’t planned to, and exposing you to the Clave would have been so much more fun—”

Something silver bloomed from Diana’s hand. A sharp-pointed throwing star. It whipped toward Malcolm; one moment he was in its path, the next he was across the room. The throwing star hit the wall of the cave and tumbled to the ground, where it lay glimmering.

Malcolm made a hissing noise, like an angry cat. Sparks flew from his fingers. Diana was lifted up into the air and flung back against the wall, then to the floor, her arms clamping themselves to her sides. She rolled into a sitting position, but when she tried to stand, her knees crumpled under her. She thrashed at her invisible bonds.

“You won’t be able to move,” Malcolm said in a bored voice. “You’re paralyzed. I could have killed you instantly, of course, but well, this is quite a trick I’m about to perform and every trick needs an audience.” He smiled suddenly. “I suppose I shouldn’t forget the audience I have. It’s just that they aren’t very lively.”

Suddenly the cavern was alive with light. The thick shadows behind the stone table dissolved, and Emma could see that the cavern reached back and back—there were long rows of seats set up, like church pews, neat and orderly, and the seats were filled with people.

“Followers,” Ty breathed. He had only seen them before out of the window of the Institute, Emma thought, and wondered what he thought of them up close. It was strange to know that Malcolm had led all these people, that he had had such power over them that they did anything for him—Malcolm, who they’d all thought of as a foolish figure, someone who tied his own shoelaces together.

The Followers sat very still, their eyes wide open, their hands in their laps, like rows of dolls. Emma recognized Belinda and some of the others who had come to retrieve Sterling. Their heads were tilted to the side—a gesture of interest, Emma thought, until she realized how awkward the angle was and knew that it wasn’t fascination that kept them so still. It was that their necks were broken.

Someone pressed forward and put a hand on Emma’s shoulder. It was Cristina. “Emma,” she whispered. “We must attack. Diego thinks we can surround Malcolm, that enough of us could bring him down—”

Emma stood paralyzed. She wanted to run forward, to attack Malcolm. But she could feel something in the back of her mind, an insistent voice, telling her to wait. It wasn’t fear. It wasn’t her own hesitation. If she hadn’t known better, if she didn’t think it would mean she was going crazy, she would have said it was Julian’s voice. Emma, wait. Please wait.

“Wait,” she whispered.

“Wait?” Cristina’s anxiety was palpable. “Emma, we need to—”

Malcolm strode into the circle. He was standing close to Tavvy’s feet, which looked bare and vulnerable in the light. He reached out to the draped object standing at the foot of the table and twitched the cloth off it.