Nate chuckled. "A prototype," he said. "Abandoned by the Magister. Too large and cumbersome for his purposes. But not for mine." He raised his voice. "Drop her."

The automaton's metal hands opened. Charlotte tumbled free and struck the ground with a sickening thump. She lay unmoving. From this distance Tessa could not tell if her chest was rising and fal ing or not.

"Now crush her," said Nate.

Ponderously the thing raised its spiked metal foot. Tessa clawed at Nate's forearms, ripping his skin with her nails.

"Charlotte!" For a moment Tessa thought the voice screaming was her own, but it was too low-pitched for that. A figure darted out from behind the automaton, a figure all in black, topped by a shock of blazing ginger hair, a thin-bladed misericord in hand.

Henry.

Without even a glance at Tessa and Nate, he launched himself at the automaton, bringing his blade down in a long curving arc. There was the clang of metal on metal. Sparks flew, and the automaton staggered back. Its foot came down, slamming into the floor, inches from Charlotte's supine body. Henry landed, then threw himself at the creature again, slashing out with his blade.

The blade shattered. For a moment Henry simply stood and looked at it with stupid shock. Then the creature's hand whipped forward and seized him by the arm. He shouted out as it lifted him and threw him with incredible force against one of the pil ars; he struck it, crumpled, and fell to the floor, where he lay still.

Nate laughed. "Such a display of matrimonial devotion," he said. "Who would have thought it? Jessamine always said she thought Branwel couldn't stand his wife."

"You're a pig," Tessa said, struggling in his grasp. "What do you know about the things people do for each other? If Jessamine were burning to death, you wouldn't look up from your card game. You care for nothing but yourself."

"Be quiet, or I'll loosen your teeth for you." Nate shook her again, and call ed out, "Come! Over here. You must hold her til the Magister arrives."

With a grinding of gears the automaton moved to obey. It was not as swift as its smaller brethren, but its size was such that Tessa could not help but fol ow its movements with an icy fear. And that was not all. The Magister was coming. Tessa wondered if Nate had summoned him yet, if he was on his way. Mortmain. Even the memory of his cold eyes, his icy, control ing smile, made her stomach turn. "Let me go," she cried, jerking away from her brother. "Let me go to Charlotte-"

Nate shoved her forward, hard, and she sprawled on the ground, her elbows and knees connecting with force with the hard wooden floor. She gasped and rol ed sideways, under the shadow of the second-floor gal ery, as the automaton lumbered toward her. She cried out- And they leaped from the gal ery above, Will and Jem, each landing on a shoulder of the creature. It roared, a sound like bel ows being fed with coal, and staggered back, all owing Tessa to rol out of its path and launch herself to her feet. She glanced from Henry to Charlotte. Henry was pale and still, crumpled beside the pil ar, but Charlotte, lying where the automaton had dropped her, was in imminent danger of being crushed by the rampaging machine.

Taking a deep breath, Tessa dashed across the room to Charlotte and knelt down, laying her fingers to Charlotte's throat; there was a pulse there, fluttering weakly. Putting her hands under Charlotte's arms, she began to drag her toward the wall, away from the center of the room, where the automaton was spinning and spitting sparks, reaching up with its pincered hands to claw at Jem and Will.

They were too quick for it, though. Tessa laid Charlotte down among the burlap sacks of tea and gazed across the room, trying to determine a path that might lead her to Henry. Nate was dashing back and forth, shouting and cursing at the mechanical creature; in answer Will sawed off one of its horns and threw it at Tessa's brother. It bounced across the floor, skittering and sparking, and Nate jumped back. Will laughed. Jem meanwhile was clinging on to the creature's neck, doing something that Tessa could not see. The creature itself was turning in circles, but it had been designed for reaching out and grabbing what was in front of it, and its "arms" did not bend properly.

It could not reach what clung to the back of its neck and head.

Tessa almost wanted to laugh. Will and Jem were like mice scurrying up and down the body of a cat, driving it to distraction. But hack and slash as they might at the metal creature with their blades, they were inflicting few injuries. Their blades, which she had seen shear through iron and steel as if they were paper, were leaving only dents and scratches on the surface of the mechanical creature's body.

Nate, meanwhile, was screaming and cursing. "Shake them off!" he yel ed at the automaton. "Shake them off, you great metal bastard!"

The automaton paused, then shook itself violently. Will slipped, catching on to the creature's neck at the last moment to keep himself from fal ing. Jem was not so lucky; he stabbed forward with his sword-cane, as if he meant to drive it into the creature's body to arrest his fall, but the blade merely skidded down the creature's back. Jem fell, gracelessly, his weapon clattering, his leg bent under him.

"James!" Will shouted.

Jem dragged himself painful y to his feet. He reached for the stele at his belt, but the creature, sensing weakness, was already on him, reaching out its clawed hands. Jem took several staggering steps backward and fumbled something out of his pocket. It was smooth, oblong, metal ic-the object Henry had given him in the library.

He reached back a hand to throw it-and Nate was behind him suddenly, kicking out at his injured, likely broken, leg. Jem didn't make a sound, but the leg went out from under him with a snapping noise and he hit the ground for a second time, the object rol ing from his hand.

Tessa scrambled to her feet and ran for it just as Nate did the same. They col ided, his greater weight and height bearing her to the floor. She rol ed as she fell, as Gabriel had taught her to, to absorb the impact, though the shock stil left her breathless. She reached for the device with shaking fingers, but it skittered away from her. She could hear Will screaming her name, call ing to her to throw it to him. She stretched her hand out farther, her fingers closing around the device-and then Nate seized her by one leg and dragged her back toward him, mercilessly.

He is bigger than I am, she thought. Stronger than I am. More ruthless than I am. But there is one thing I can do that he cannot.

She Changed.

She reached out with her mind for the grip of his hand on her ankle, his skin touching her own. She reached out for the intrinsic, inborn Nate that she had always known, that spark inside him that flickered the way it did inside everyone, like a candle in a dark room. She heard him suck in his breath, and then the Change took her, rippling her skin, melting her bones. The buttons at her col ar and cuffs snapped as she grew in size, convulsions thrashing through her limbs, ripping her leg free of Nate's grasp. She rol ed away from her brother, staggering to her feet, and saw his eyes widen as he looked at her.

She was now, other than her clothes, an exact mirror image of himself.

She whirled on the automaton. It was frozen, waiting for instructions, Will stil clinging to its back. He raised his hand, and Tessa threw the device, silently thanking Gabriel and Gideon for the hours of knife throwing instruction. It flew through the air in a perfect arc, and Will caught it out of the sky.

Nate was on his feet. "Tessa," he snarled. "What in the bloody hel do you possibly think you're-"

"Seize him!" she shouted at the automaton, pointing at Nate. "Catch him and hold him!"

The creature did not move. Tessa could hear nothing but Nate's harsh breathing beside her, and the sound of clanking from the metal creature; Will had vanished behind it and was doing something, though she could not see what.

"Tessa, you're a fool," Nate hissed. "This cannot work. The creature is obedient only to-"

"I am Nathaniel Gray!" Tessa shouted up at the metal giant. "And I order you in the name of the Magister to seize this man and hold him!"

Nate whirled on her. "Enough of your games, you stupid little-"

His words were cut off suddenly as the automaton bent and seized him in its pincered grasp. It lifted him up, up, level with its slash of a mouth clicking and whirring inquisitively. Nate began to scream, and kept screaming, witlessly, his arms flailing as Will, finished with whatever he was doing, dropped to the ground in a crouch. He shouted something at Tessa, his blue eyes wide and wild, but she couldn't hear him over her brother's screams.

Her heart was slamming against her chest; she felt her hair tumble down, hitting her shoulders with a soft, heavy weight. She was herself again, the shock of what was happening too great for her to hold on to the Change.

Nate was still screaming-the thing had him in a terrible pincer grip. Will had begun to run, just as the creature, staring at Tessa, reared up with a roar- and Will struck her, knocking her to the ground and covering her with his body as the automaton blew apart like an exploding star.

The cacaphony of bursting, clattering metal was incredible. Tessa tried to cover her ears, but Will 's body was pinning her firmly to the ground. His elbows dug into the floor on either side of her head. She felt his breath on the back of her neck, the pounding of his heart against her spine. She heard her brother cry out, a terrible gurgling cry. She turned her head, pressing her face into Will 's shoulder as his body jerked against hers; the floor shuddered beneath them- And it was over. Slowly Tessa opened her eyes. The air was cloudy with plaster dust and floating splinters and tea from torn burlap sacks. Huge chunks of metal lay scattered haphazardly about the floor, and several of the windows had burst open, letting in foggy evening light. Tessa's glance darted about the room. She saw Henry, cradling Charlotte, kissing her pale face as she gazed up at him; Jem, struggling to his feet, stele in hand and plaster dust coating his clothes and hair-and Nate.

At first she thought he was leaning against one of the pil ars. Then she saw the spreading red stain across his shirt, and realized. A jagged chunk of metal had gone through him like a spear, pinning him upright to the pil ar. His head was down, his hands clawing weakly at his chest.

"Nate!" she screamed. Will rol ed sideways, freeing her, and she was on her feet in seconds, racing across the room to her brother. Her hands were shaking with horror and revulsion, but she managed to close them around the metal spear in his chest and pul it free. She threw it aside and barely succeeded in catching him as he slumped forward, his sudden dead weight bearing her to the ground. Somehow she found herself on the ground, Nate's limp body stretched awkwardly across her lap.

A memory rose in her mind-her crouching on the floor at de Quincey's town house, holding Nate in her arms. She had loved him then. Trusted him.

Now, as she held him and his blood soaked into her shirt and trousers, she felt as if she were watching actors on a stage, playing parts, acting out grief.

"Nate," she whispered.

His eyes fluttered open. A pang of shock went through her. She had thought he was already dead.

"Tessie . . ." His voice sounded thick, as if it were coming through layers of water. His eyes roamed her face, then the blood on her clothes, and then, final y, came to rest on his own chest, where blood pumped steadily through a massive rent in his shirt. Tessa shrugged off her jacket, wadded it up, and pressed it hard against the wound, praying it would be enough to make the blood stop.

It wasn't. The jacket was soaked through instantly, thin wet streams of blood running down Nate's sides. "Oh, God," Tessa whispered. She raised her voice. "Wil -"

"Don't." Nate's hand seized her wrist, his nails digging in.

"But, Nate-"

"I'm dying. I know." He coughed, a loose, wet, rattling sound. "Don't you understand? I've failed the Magister. He'l kil me anyway. And he'l make it slow." He made a hoarse, impatient noise. "Leave it, Tessie. I'm not being noble. You know I'm not that."

She took a ragged breath. "I should leave you here to die alone in your own blood. That's what you'd do if it were me."

"Tessie-" A stream of blood spilled from the corner of his mouth. "The Magister was never going to hurt you."

"Mortmain," she whispered. "Nate, where is he? Please. tell me where he is."

"He-" Nate choked, heaving in a breath. A bubble of blood appeared on his lips. The jacket in Tessa's hand was a sodden rag. His eyes went wide, starkly terrified. "Tessie . . . I-I'm dying. I'm really dying-"

Questions still exploded through her head. Where is Mortmain? How could my mother be a Shadowhunter? If my father was a demon, how is it that I am still alive when all the offspring of Shadowhunters and demons are stillborn? But the terror in Nate's eyes silenced her; despite everything, she found her hand slipping into his. "There's nothing to be afraid of, Nate."

"Not for you, maybe. You were always-the good one. I'm going to burn, Tessie. Tessie, where's your angel?"

She put her hand to her throat, a reflexive gesture. "I couldn't wear it. I was pretending to be Jessamine."

"You-must-wear it." He coughed. More blood. "Wear it always. You swear?"

She shook her head. "Nate . . ." I can't trust you, Nate.

"I know." His voice was a bare rattle. "There's no forgiveness for-the kinds of things I've had to do."

She tightened her grip on his hand, her fingers slippery with his blood. "I forgive you," she whispered, not knowing, or caring, if it was true.

His blue eyes widened. His face had gone the color of old yel ow parchment, his lips almost white. "You don't know everything I've done, Tessie."

She leaned over him anxiously. "Nate?"

But there was no reply. His face went slack, his eyes wide, half-rol ed-back in his head. His hand slid out of hers and struck the floor.

"Nate," she said again, and put her fingers to the place where his pulse should have beat in his throat, already knowing what she would find.

There was nothing. He was dead.

Tessa stood up. Her torn waistcoat, her trousers, her shirt, even the ends of her hair, were soaked with Nate's blood. She felt as numb as if she had been dipped in ice-cold water. She turned, slowly, only now, and for the first time, wondering if the others had been watching her, overhearing her conversation with Nate, wondering- They weren't even looking in her direction. They were kneeling-Charlotte, Jem, and Henry-in a loose circle around a dark shape on the floor, just where she had been lying before, with Will on top of her.

Will.