“I suppose,” Tessa said, “if it had been your decision to make …”

“You’d have been out the door with nothing but the key of the street to your name,” Jessamine said, and sniffed. Seeing the way Sophie was looking at her, she added, “Oh, really! Don’t be such a mush-mouth, Sophie. Agatha and Thomas would still be alive if I’d been in charge, wouldn’t they?”

Sophie went pale, her scar standing out along her cheek like the mark of a slap. “Thomas is dead?”

Jessamine looked as if she knew she’d made a mistake. “I didn’t mean that.”

Tessa looked at her, hard. “What happened, Jessamine? We saw you injured—”

“And precious little any of you did about it either,” Jessamine said, and sat down with a flounce on the fountain wall, apparently forgetting to worry about the state of her dress. “I was unconscious … and when I awoke, I saw that all of you had gone but Thomas. Mortmain was gone too, but those creatures were still there. One of them began to come after me, and I looked for my parasol, but it had been trampled to shreds. Thomas was surrounded by those creatures. I went toward him, but he told me to run, so … I ran.” She tilted her chin up defiantly.

Sophie’s eyes flashed. “You left him there? Alone?”

Jessamine set the knife down on the wall with an angry clatter. “I’m a lady, Sophie. It is expected that a man sacrifice himself for a lady’s safety.”

“That’s rubbish!” Sophie’s hands were tight little fists at her sides. “You’re a Shadowhunter! And Thomas is just a mundane! You could have helped him. You just wouldn’t—because you’re selfish! And—and awful!”

Jessamine gaped at Sophie, her mouth wide open. “How dare you speak to me like—”

She broke off as the door of the Sanctuary resounded with the noise of the heavy knocker falling. It sounded again, and then a familiar voice, raised, called out to them, “Tessa! Sophie! It’s Will.”

“Oh, thank God,” Jessamine said—clearly just as relieved to be free of her conversation with Sophie as she was to be rescued—and hurried toward the door. “Will! It’s Jessamine. I’m in here too!”

“And you’re all three all right?” Will sounded anxious in a way that tightened Tessa’s chest. “What happened? We raced here from Highgate. I saw the door of the Institute open. How in the Angel’s name did Mortmain get in?”

“He evaded the wards somehow,” Jessamine said bitterly, reaching for the door handle. “I’ve no idea how.”

“It hardly matters now. He’s dead. The clockwork creatures are destroyed.”

Will’s tone was reassuring—so why, Tessa thought, did she not feel reassured? She turned to look at Sophie, who was staring at the door, a sharp vertical frown line between her eyes, her lips moving very slightly as if she were whispering something under her breath. Sophie had the Sight, Tessa remembered—Charlotte had said so. Tessa’s sense of unease rose and crested like a wave.

“Jessamine,” she called. “Jessamine, don’t open the door—”

But it was too late. The door had swung wide. And there on the threshold stood Mortmain, flanked by clockwork monsters.

Thank the Angel for glamours, Will thought. The sight of a boy riding bareback on a charging black horse down Farringdon Road would normally be enough to raise eyebrows even in a metropolis as jaded as London. But as Will went by—the horse kicking up great puffs of London dust as it reared and snorted its way through the streets—no one turned a hair or batted the lash of an eye. Yet even as they seemed not to see him, they found reasons to move out of his way—a dropped pair of eyeglasses, a step to the side to avoid a puddle in the road—and avoid being trampled.

It was almost five miles from Highgate to the Institute; it had taken them three-quarters of an hour to cover the distance in the carriage. It took Will and Balios only twenty minutes to make the return trip, though the horse was panting and lathered with sweat by the time Will pounded through the Institute gates and drew up in front of the steps.

His heart sank immediately. The doors were open. Wide open, as if inviting in the night. It was strictly against Covenant Law to leave the doors of an Institute standing ajar. He had been correct; something was terribly wrong.

He slid from the horse’s back, boots clattering loudly against the cobblestones. He looked for a way to secure the animal, but as he’d cut its harness, there was none, and besides, Balios looked inclined to bite him. He shrugged and made for the steps.

Jessamine gasped and leaped back as Mortmain stepped into the room. Sophie screamed and ducked behind a pillar. Tessa was too shocked to move. The four automatons, two on either side of Mortmain, stared straight ahead with their shining faces like metal masks.

Behind Mortmain was Nate. A makeshift bandage, stained with blood, was tied around his head. The bottom of his shirt—Jem’s shirt—had a ragged strip torn from it. His baleful gaze fell on Jessamine.

“You stupid whore,” he snarled, and started forward.

“Nathaniel.” Mortmain’s voice cracked like a whip; Nate froze. “This is not an arena in which to enact your petty revenges. There is one more thing I need from you; you know what it is. Retrieve it for me.”

Nate hesitated. He was looking at Jessamine like a cat with its gaze fixed on a mouse.

“Nathaniel. To the weapons room. Now.”

Nate dragged his gaze from Jessie. For a moment he looked at Tessa, the rage in his expression softening into a sneer. Then he turned on his heel and stalked from the room; two of the clockwork creatures peeled themselves from Mortmain’s side and followed him.

The door closed behind him, and Mortmain smiled pleasantly. “The two of you,” he said, looking from Jessamine to Sophie, “get out.”

“No.” The voice was Sophie’s, small but stubborn, though to Tessa’s surprise, Jessamine showed no inclination to leave either. “Not without Tessa.”

Mortmain shrugged. “Very well.” He turned to the clockwork creatures. “The two girls,” he said. “The Shadowhunter and the servant. Kill them both.”

He snapped his fingers and the clockwork creatures sprang forward. They had the grotesque speed of skittering rats. Jessamine turned to run, but she had gone only a few steps when one of them seized her, lifting her off the ground. Sophie darted among the pillars like Snow White fleeing into the woods, but it did her little good. The second creature caught up to her swiftly and bore her to the ground as she screamed. In contrast Jessamine was utterly silent; the creature holding her had one metal hand clamped across her mouth and the other around her waist, fingers digging in cruelly. Her feet kicked uselessly in the air like the feet of a criminal dangling at the end of a hangman’s rope.

Tessa heard her own voice as it emerged from her throat as if it were a stranger’s. “Stop it. Please, please, stop it!”

Sophie had broken away from the creature holding her and was scrambling across the floor on her hands and knees. Reaching out, it caught her by the ankle and jerked her backward across the floor, her apron tearing as she sobbed.

“Please,” Tessa said again, fixing her eyes on Mortmain.

“You can stop it, Miss Gray,” he said. “Promise me you won’t try to run.” His eyes burned as he looked at her. “Then I’ll let them go.”

Jessamine’s eyes, visible above the metal arm clamping her mouth, pleaded with Tessa. The other creature was on its feet, holding Sophie, who dangled limply in its grip.

“I’ll stay,” Tessa said. “You have my word. Of course I will. Just let them go.”

There was a long pause. Then, “You heard her,” Mortmain said to his mechanical monsters. “Take the girls out of this room. Bring them downstairs. Don’t harm them.” He smiled then, a thin, crafty smile. “Leave Miss Gray alone with me.”

Even before he passed through the front doors, Will felt it—the jangling sense that something dreadful was happening here. The first time he’d ever felt this sensation, he’d been twelve years old, holding that blasted box—but he’d never imagined feeling it in the fastness of the Institute.

He saw Agatha’s body first, the moment he stepped over the threshold. She lay on her back, her glassy eyes staring up at the ceiling, the front of her plain gray dress soaked with blood. A wave of almost overwhelming rage washed over Will, leaving him light-headed. Biting his lip hard, he bent to close her eyes before he rose and looked around.

The signs of a melee were everywhere—torn scraps of metal, bent and broken gears, splashes of blood mixing with pools of oil. As Will moved toward the stairs, his foot came down on the shredded remains of Jessamine’s parasol. He gritted his teeth and moved on to the staircase.

And there, slumped across the lowest steps, lay Thomas, eyes closed, motionless in a widening pool of scarlet. A sword rested on the ground beside him, a little ways away from his hand; its edge was chipped and dented as if he had been using it to hack apart rocks. A great jagged piece of metal protruded from his chest. It looked a little like the torn blade of a saw, Will thought as he crouched down by Thomas’s side, or like a sharp bit of some larger metal contraption.

There was a dry burning in the back of Will’s throat. His mouth tasted of metal and rage. He rarely grieved during a battle; he saved his emotions for afterward—those he had not already learned to bury so deeply that he barely felt them at all. He had been burying them since he was twelve years old. His chest knotted with pain now, but his voice was steady when he spoke. “Hail and farewell, Thomas,” he said, reaching to close the other boy’s eyes. “Ave—”

A hand flew up and gripped his wrist. Will stared down, dumbfounded, as Thomas’s glassy eyes slid toward him, pale brown under the whitish film of death. “Not,” he said, with a clear effort to get the words out, “a Shadowhunter.”

“You defended the Institute,” Will said. “You did as well as any of us would have done.”

“No.” Thomas closed his eyes, as if exhausted. His chest rose, barely; his shirt was soaked almost black with blood. “You’d’ve fought ’em off, Master Will. You know you would.”

“Thomas,” Will whispered. He wanted to say, Be quiet, and you’ll be all right when the others get here. But Thomas manifestly would not be all right. He was human; no healing rune could help him. Will wished that Jem were here, instead of himself. Jem was the one you wanted with you when you were dying. Jem could make anyone feel that things were going to be all right, whereas Will privately suspected that there were few situations that his presence did not make worse.

“She’s alive,” Thomas said, not opening his eyes.

“What?” Will was caught off guard.

“The one you come back for. Her. Tessa. She’s with Sophie.” Thomas spoke as if it were a fact obvious to anyone that Will would have come back for Tessa’s sake. He coughed, and a great mass of blood poured out of his mouth and down his chin. He didn’t seem to notice. “Take care of Sophie, Will. Sophie is—”