A gasp ran through the room. Dozens of white faces swung toward Tessa. Her scream had broken through their bloodlust. De Quincey was motionless on the stage; even Nathaniel was looking at her, dazed and staring, as if wondering if her screams were a dream born out of his agony.

Will, his finger on the button of the Phosphor, hesitated. His eyes met Tessa’s across the room. It was only for a split second, but de Quincey saw their glance. As if he could read it, the look on his face changed, and he swung his hand up to point directly at Will.

“The boy,” he spat. “Stop him!”

Will tore his gaze from Tessa’s. The vampires were already rising to their feet, moving toward him, their eyes glittering with rage and hunger. Will looked past them, at de Quincey, who was staring at Will with fury. There was no fear on Will’s face as his gaze met the vampire’s—no hesitation, and no surprise.

“I am not a boy,” he said. “I am Nephilim.”

And he pressed the button.

Tessa braced herself for a flare of white witchlight. Instead there was a great whoosh of sound as the flames of the candelabras shot toward the ceiling. Sparks flew, scattering the floor with glowing embers, catching in the curtains, in the skirts of women’s dresses. Suddenly the room was full of billowing black smoke and screams—high-pitched and horrible.

Tessa could no longer see Will. She tried to dart forward, but Magnus—she had nearly forgotten he was there—caught her firmly by the wrist. “Miss Gray, no,” he said, and when she responded by pulling away harder, he added, “Miss Gray! You’re a vampire now! If you catch fire, you’ll go up like kindling wood—”

As if to illustrate his point, at that moment a stray spark landed atop Lady Delilah’s white wig. It burst into flames. With a cry she tried to rip it from her head, but as her hands came in contact with the flames, they, too, caught fire as if they were made of paper instead of skin. In less than a second both her arms were burning like torches. Howling, she raced toward the door, but the fire was faster than she was. Within seconds a bonfire raged where she had stood. Tessa could just see the outline of a blackened screaming creature writhing inside it.

“Do you see what I mean?” Magnus shouted in Tessa’s ear, struggling to make himself heard over the howls of the vampires, who were diving this way and that, trying to avoid the flames.

“Let me go!” Tessa shrieked. De Quincey had leaped into the melee; Nathaniel was slumped alone onstage, apparently unconscious, only his manacles holding him to the chair. “That’s my brother up there. My brother!”

Magnus stared at her. Taking advantage of his confusion, Tessa jerked her arm free and began to run toward the stage. The room was chaos: vampires rushing to and fro, many of them stampeding toward the doorway. The vampires who had reached the door were pushing and shoving to get through it first; others had turned course and were streaming toward the French doors that looked out over the garden.

Tessa veered to avoid a fallen chair, and nearly ran headlong into the redheaded vampire in the blue dress who had glared at her earlier. She looked terrified now. She plunged toward Tessa—then seemed to stumble. Her mouth opened in a scream, and blood poured from it like a fountain. Her face crumpled, folding in on itself, the skin resolving into dust and raining down from the bones of her skull. Her red hair shriveled and turned gray; the skin of her arms melted and turned to powder, and with a last despairing shriek the vampire woman collapsed into a stringy heap of bones and dust lying atop an empty satin dress.

Tessa gagged, tore her eyes away from the remains, and saw Will. He stood directly in front of her, holding a long silver knife; the blade was smeared with scarlet blood. His face was bloody too, his eyes wild. “What the hell are you still doing here?” he shouted at Tessa. “You unbelievably stupid—”

Tessa heard the noise before Will did, a thin whining sound, like a piece of broken machinery. The fair-haired boy in the gray jacket—the human servant Lady Delilah had drunk from earlier—was rushing at Will, a high-pitched wailing sound coming from his throat, his face smeared with tears and blood. He was carrying a torn-off chair leg in one hand; the end of it was ragged and sharp.

“Will, look out!” Tessa shouted, and Will spun. He moved fast, Tessa saw, like a dark blur, and the knife in his hand was a flash of silver in the smoky dimness. When he stopped moving, the boy was lying on the ground, the blade protruding from his chest. Blood welled around it, thicker and darker than vampire blood.

Will, staring down, was ashen. “I thought …”

“He would have killed you if he could,” Tessa said.

“You know nothing of it,” Will said. He shook his head, once, as if clearing it of her voice, or of the sight of the boy on the ground. The subjugate looked very young, his twisted face softer in death. “I told you to go—”

“That’s my brother,” Tessa said, pointing toward the back of the room. Nathaniel was still unconscious, limp in his manacles. If it weren’t for the blood still flowing from the wound in his neck, she would have thought he was dead. “Nathaniel. In the chair.”

Will’s eyes widened in astonishment. “But how—?” he began. He didn’t get a chance to finish his question. At that moment the sound of shattering glass filled the room. The French windows burst inward, and the room was suddenly flooded with Shadowhunters in their dark fighting gear. They were driving before them in a screaming, ragged group the vampires who had fled into the garden. As Tessa stared, more Shadowhunters began flooding in from the other doors as well, herding more vampires in front of them, like dogs herding sheep into a pen. De Quincey staggered before the other vampires, his pale face smeared with black ash, his teeth bared.

Tessa saw Henry among the Nephilim, easily recognizable by his ginger hair. Charlotte was there too, dressed like a man all in dark fighting gear, like the women pictured in Tessa’s Shadowhunter book. She looked small and determined and surprisingly fierce. And then there was Jem. His gear made him appear all the more startlingly pale, and the black Marks on his skin stood out like ink on paper. In the crowd she recognized Gabriel Lightwood; his father, Benedict; slim black-haired Mrs. Highsmith; and behind them all strode Magnus, blue sparks flying from his hands as he gestured.

Will exhaled, some of the color returning to his face. “I wasn’t sure they’d come,” he muttered, “not with the Phosphor malfunctioning.” He tore his eyes away from his friends and looked at Tessa. “Go attend to your brother,” he said. “That’ll get you out of the worst of it. I hope.”

He turned and walked away from her without a backward glance. The Nephilim had herded the remaining vampires, those who had not been killed by the fire—or by Will—into the center of a makeshift circle of Shadowhunters. De Quincey towered among the group, his pale face twisted in rage; his shirt was stained with blood—his own or someone else’s, she couldn’t tell. The other vampires huddled behind him like children behind a parent, looking both fierce and wretched at the same time.

“The Law,” de Quincey growled, as Benedict Lightwood advanced on him, a shining blade in his right hand, its surface scored with black runes. “The Law protects us. We surrender to you. The Law—”

“You have broken the Law,” snarled Benedict. “Therefore its protection no longer extends to you. The sentence is death.”

“One mundane,” said de Quincey, sparing a glance toward Nathaniel. “One mundane who has also broken Covenant Law—”

“The Law does not extend to mundanes. They cannot be expected to follow the laws of a world they know nothing of.”

“He is worthless,” de Quincey said. “You do not know how worthless. Do you really desire to shatter our alliance over one worthless mundane?”

“It is more than just one mundane!” Charlotte cried, and from her jacket she drew the paper Will had taken from the library. Tessa had not seen Will pass it to Charlotte, but he must have. “What of these spells? Did you think we would not discover them? This—this black sorcery is absolutely forbidden by the Covenant!”

De Quincey’s still face betrayed only a hint of his surprise. “Where did you find that?”

Charlotte’s mouth was a hard thin line. “That doesn’t matter.”

“Whatever it is you think you know—,” de Quincey began.

“We know enough!” Charlotte’s voice was full of passion. “We know you hate and despise us! We know your alliance with us has been a sham!”

“And have you made it against Covenant Law now to dislike Shadowhunters?” de Quincey said, but the sneer was gone from his voice. He sounded ragged.

“Do not play your games with us,” spat Benedict. “After all we’ve done for you, after we passed the Accords into Law—Why? We’ve tried to make you equal to ourselves—”

De Quincey’s face twisted. “Equal? You don’t know what the word means. You cannot let go of your own conviction, let go of your belief in your inherent superiority, for long enough to even consider what that would mean. Where are our seats on the Council? Where is our embassy in Idris?”

“But that—that’s ridiculous,” Charlotte said, though she had blanched.

Benedict shot Charlotte an impatient look. “And irrelevant. None of this excuses your behavior, de Quincey. While you sat in council with us, pretending you were interested in peace, behind our backs you broke the Law and mocked our power. Surrender yourself, tell us what we want to know, and we might let your clan survive. Otherwise, there will be no mercy.”

Another vampire spoke. It was one of the men who had strapped Nathaniel to his chair, a big flame-haired man with an angry face. “If we needed any further proof that the Nephilim have never meant their promises of peace, here it is. Dare to attack us, Shadowhunters, and you’ll have a war on your hands!”

Benedict only grinned. “Then let the war begin here,” he said, and flung the blade at de Quincey. It whipped through the air—and plunged hilt-deep into the chest of the redheaded vampire, who had flung himself in front of his clan leader. He exploded in a shower of blood as the other vampires shrieked. With a howl de Quincey rushed Benedict. The other vampires seemed to awaken from their panicked stupor, and swiftly followed suit. Within seconds the room was a melee of screams and chaos.

The sudden chaos unfroze Tessa as well. Catching up her skirts, she ran for the stage, and dropped to her knees next to Nathaniel’s chair. His head lolled to the side, his eyes closed. The blood from the wound in his neck had flowed to a slow trickle. Tessa caught at his sleeve. “Nate,” she whispered. “Nate, it’s me.”

He moaned, but made no other reply. Biting her lip, Tessa went to work on the manacles that fastened his wrists to the chair. They were hard iron, fastened to the sturdy chair arms with rows of nails—clearly designed to withstand even vampire strength. She pulled at them until her fingers bled, but they didn’t budge. If only she had one of Will’s knives.