The foyer was filled with Shadowhunters. Some, familiar to her as the Nephilim of the Los Angeles Conclave, in black, others in red gear. There were rows of statuary, now toppled over, in pieces and powder on the ground. The picture window that opened onto the sea had been smashed, and broken glass and blood were everywhere.

Emma felt a sick lurch in her stomach. In the middle of the foyer stood a tall figure in scarlet. He was pale blond, almost white-haired, and his face looked like the carved marble face of Raziel, only entirely without mercy. His eyes were coal black, and in one hand he carried a sword stamped with a pattern of stars; in the other, a goblet made of shimmering adamas.

The sight of the cup triggered something in Emma’s mind. The adults didn’t like to talk about politics around the younger Shadowhunters, but she knew that Valentine Morgenstern’s son had taken on a different name and sworn vengeance against the Clave. She knew that he had made a cup that was the reverse of the Angel’s Cup, that changed Shadowhunters into evil, demonic creatures. She had heard Mr. Blackthorn call the evil Shadowhunters the Endarkened Ones; he had said he’d rather die than be one.

This was him, then. Jonathan Morgenstern, whom everyone called Sebastian—a figure out of a fairy tale, a story told to frighten children, come to life. Valentine’s son.

Emma put a hand to the back of Tavvy’s head, pressing his face into her shoulder. She couldn’t move. She felt as if lead weights were attached to her feet. All around Sebastian were Shadowhunters in black and red, and figures in dark cloaks—were they Shadowhunters, too? She couldn’t tell—their faces were hidden, and there was Mark, his hands being held behind his back by a Shadowhunter in red gear. His daggers lay at his feet, and there was blood on his training clothes.

Sebastian raised a hand and crooked a long white finger. “Bring her,” he said; there was a rustle in the crowd, and Mr. Blackthorn stepped forward, dragging Katerina with him. She was fighting, beating at him with her hands, but he was too strong. Emma watched in disbelieving horror as Mr. Blackthorn pushed her to her knees.

“Now,” said Sebastian in a voice like silk, “drink of the Infernal Cup,” and he forced the rim of the cup between Katerina’s teeth.

That was when Emma found out what the terrible howling noise she had heard before was. Katerina tried to fight free, but Sebastian was too strong; he jammed the cup past her lips, and Emma saw her gasp and swallow. She wrenched away, and this time Mr. Blackthorn let her; he was laughing, and so was Sebastian. Katerina fell to the ground, her body spasming, and from her throat came a single scream—worse than a scream, a howl of pain as if her soul were being torn out of her body.

A laugh went around the room; Sebastian smiled, and there was something horrible and beautiful about him, the way there was something horrible and beautiful about poisonous snakes and great white sharks. He was flanked by two companions, Emma realized: a woman with graying brown hair, an axe in her hands, and a tall figure wrapped entirely in a black cloak. No part of him was visible except the dark boots that showed beneath the hem of his robe. Only his height and breadth made her think he was a man at all.

“Is that the last of the Shadowhunters here?” Sebastian asked.

“There is the boy, Mark Blackthorn,” said the woman standing beside him, raising a finger and pointing at Mark. “He ought to be old enough.”

Sebastian looked down at Katerina, who had stopped spasming and lay still, her dark hair tangled across her face. “Get up, sister Katerina,” he said. “Go and bring Mark Blackthorn to me.”

Emma watched, rooted to the spot, as Katerina rose slowly to her feet. Katerina had been the tutor at the Institute for as long as Emma could remember; she had been their teacher when Tavvy had been born, when Jules’s mother had died, when Emma had first started physical training. She had taught them languages and bound up cuts and soothed scrapes and given them their first weapons; she had been like family, and now she stepped, blank-eyed, across the mess on the floor and reached out to seize Mark.

Dru gave a gasp, snapping Emma back to consciousness. Emma whirled, and placed Tavvy in Dru’s arms; Dru staggered a little and then recovered, clutching her baby brother tight. “Run,” Emma said. “Run to the office. Tell Julian I’ll be right there.”

Something of the urgency in Emma’s voice communicated itself; Drusilla didn’t argue, just clutched Tavvy more tightly and fled, her bare little feet soundless on the corridor floors. Emma spun back to stare down at the unfolding horror. Katerina was behind Mark, pushing him ahead, a dagger pressed to the space between his shoulder blades. He staggered and nearly stumbled in front of Sebastian; Mark was closer to the steps now, and Emma could see that he had been fighting. There were defensive wounds on his wrists and hands, cuts on his face, and there had doubtless been no time for healing runes. There was blood all over his right cheek; Sebastian looked at him, lip curling in annoyance.

“This one is not all Nephilim,” he said. “Part faerie, am I correct? Why was I not informed?”

There was a murmur. The brown-haired woman said, “Does it mean the Cup will not work on him, Lord Sebastian?”

“It means I don’t want him,” said Sebastian.

“We could take him to the valley of salt,” said the brown-haired woman. “Or to the high places of Edom, and sacrifice him there for the pleasure of Asmodeus and Lilith.”

“No,” Sebastian said slowly. “No, it would not be wise, I think, to do that to one with the blood of the Fair Folk.”

Mark spat at him.

Sebastian looked startled. He turned to Julian’s father. “Come and restrain him,” he said. “Wound him if you desire. I shall have only so much patience with your half-breed son.”

Mr. Blackthorn stepped forward, holding a broadsword. The blade was already stained with blood. Mark’s eyes widened with terror. The sword rose up—

The throwing knife left Emma’s hand. It flew through the air, and buried itself in Sebastian Morgenstern’s chest.

Sebastian staggered back, and Mr. Blackthorn’s sword hand fell to his side. The others were crying out; Mark leaped to his feet as Sebastian looked down at the blade in his chest, its handle protruding from his heart. He frowned.

“Ouch,” he said, and pulled the knife free. The blade was slick with blood, but Sebastian himself looked unbothered by the injury. He cast the weapon aside, staring upward. Emma felt those dark, empty eyes on her, like the touch of cold fingers. She felt him take the measure of her, sum her up and know her, and dismiss her.

“It’s a shame you won’t live,” he said to her. “Live to tell the Clave that Lilith has strengthened me beyond all measure. Perhaps Glorious could end my life. A pity for the Nephilim that they have no more favors they can ask of Heaven, and none of the puny instruments of war they forge in their Adamant Citadel can harm me now.” He turned to the others. “Kill the girl,” he demanded, flicking at his now bloody jacket with distaste.

Emma saw Mark lunge for the stairs, trying to get to her first, but the dark figure at Sebastian’s side had already seized Mark and was drawing him backward with black-gloved hands; those arms went around Mark, held him, almost as if protecting him. Mark was struggling, and then he was lost to Emma’s view as the Endarkened surged up the steps.