It was strange, different this time as the transformation took hold. The darkness rose quickly, wrapping itself around her, and the light she saw in the distance was a cold silver glow. The chill that flowed from the light was scalding. Tessa drew the light toward her, surrounding herself with its icy burning light, pushing herself through to the core of it. The light rose in shimmering white walls around her—

She felt a sharp pain then, in the center of her chest, and for a moment her vision went red—deep scarlet, the color of blood. Everything was blood-colored, and she began to panic, fighting her way free, her eyelids flying open—

And she was there again, in the Sanctuary Room, with all the others staring at her. Camille was smiling slightly; the others looked startled, if not as thunderstruck as they had when she had transformed into Jessamine.

But something was terribly wrong. There was a great hollow emptiness inside her—not pain, but a cavernous sense of something missing. Tessa choked, and a searing shock went through her. She sank down into an armchair, her hands pressed against her chest. She was trembling all over.

“Tessa?” Jem sank down onto his heels beside the chair, taking one of her hands. She could see herself in the mirror that hung on the opposite wall—or more accurately, she could see the image of Camille. Camille’s shimmering pale hair, unpinned, rained down over her shoulders, and her white skin swelled and spilled over the bodice of Tessa’s now too-tight dress in a way that would have made Tessa flush—if she could have flushed. But blushing required blood actually running in one’s veins, and she remembered, with a dawning terror, that vampires did not breathe, did not get hot or cold, and did not have hearts that beat in their chests.

So that was the hollowness, the strangeness that she felt. Her heart was still, in her chest like a dead thing. She took another sobbing breath. It hurt, and she realized that while she could breathe, her new body did not want or need to.

“Oh, God,” she said in a soft whisper to Jem. “I—my heart’s not beating. I feel as if I’ve died. Jem—”

He stroked her hand, carefully, soothingly, and looked up at her with his silver eyes. The expression in them had not changed with the change in her; he looked at her as he had before, as if she were still Tessa Gray. “You’re alive,” he said, in a voice so soft only she could hear it. “You’re wearing a different skin, but you’re Tessa, and you’re alive. Do you know how I know that?”

She shook her head.

“Because you said the word ‘God’ just now to me. No vampire could say that.” He squeezed her hand. “Your soul is still the same.”

She closed her eyes and sat still for a moment, concentrating on the pressure of his hand on hers, his warm skin against hers that was icy cold. Slowly the trembling that shook her body began to fade; she opened her eyes, and gave Jem a faint, shaky smile.

“Tessa,” said Charlotte. “Are you— Is everything all right?”

Tessa drew her eyes away from Jem’s face and looked at Charlotte, who was watching her with an anxious gaze. Will, beside Charlotte, wore an unreadable expression.

“You will have to practice a bit, moving and holding yourself, if you wish to convince de Quincey that you are me,” Lady Belcourt said. “I would never slump in a chair like that.” She tilted her head to the side. “Still, overall, an impressive showing. Someone trained you well.”

Tessa thought of the Dark Sisters. Had they trained her well? Had they done her a favor, unlocking this dormant power inside her, despite how much she had hated them and it? Or would it have been better if she had never known that she was different?

Slowly she let go, let the Camille skin slip away from her. It felt as if she were rising up out of icy water. Her hand tightened on Jem’s as the chill ran through her, head to toe, a freezing cascade. Something leaped inside her chest then. Like a bird that has lain stunned and motionless after flying into a window, only to gather its strength and leap from the ground to soar into the air, her heart began suddenly to beat again. Air filled her lungs, and she released Jem, her hands flying to her chest, her fingers pressed against the skin to feel the soft rhythm beneath.

She looked in the mirror across the room. She was herself again: Tessa Gray, not a miraculously beautiful vampire. She felt an overwhelming relief.

“My necklace?” Lady Belcourt said coolly, and held out her slender hand. Jem took the ruby pendant from Tessa to bring it to the vampire; as he lifted it, Tessa saw that there were words etched on the silver frame of the pendant: AMOR VERUS NUMQUAM MORITUR.

She looked across the room at Will, she wasn’t sure why, only to find that he was looking back at her. They both glanced hastily away. “Lady Belcourt,” Will said, “since none of us have ever been in de Quincey’s home, do you think it would be possible for you to provide a floor plan, or even a sketch of the grounds and rooms?”

“I shall provide you with something better.” Lady Belcourt raised her arms to clasp the necklace around her throat. “Magnus Bane.”

“The warlock?” Charlotte’s eyebrows rose.

“Indeed,” said Lady Belcourt. “He knows the town house as well as I do and is often invited to de Quincey’s social events. Though, like me, he has formerly eschewed the parties at which murder is committed.”

“Noble of him,” muttered Will.

“He will meet you there, and guide you through the house. No one there will be surprised to see us together. Magnus Bane is my lover, you see.”

Tessa’s mouth opened slightly. This was not the sort of thing ladies said in polite company, or any company. But perhaps it was different for vampires? Everyone else looked as stunned as she did, except Will, who as usual looked as if he were trying not to laugh.

“How nice,” Charlotte said at last, after a pause.

“Indeed it is,” Camille said, and rose to her feet. “And now, if someone will escort me out. It grows late, and I have not yet fed.”

Charlotte, who was regarding Tessa with concern, said, “Will, Jem, if you’ll go?”

Tessa watched as the two boys flanked Camille like soldiers—which, she supposed, was what they were—and followed her from the room. Last through the door, the vampire paused and looked back over her shoulder. Her pale blond curls brushed her cheeks as she smiled; she was so beautiful that Tessa felt a sort of pang, looking at her, overriding her instinctive feeling of aversion.

“If you do this,” said Camille, “and you succeed—whether or not you find your brother—I can promise you, little shape-shifter, that you won’t regret it.”

Tessa frowned, but Camille was already gone. She moved so fast that it was as though she had vanished between one breath and the next. Tessa turned toward Charlotte. “What do you think she meant by that? That I won’t regret it?”

Charlotte shook her head. “I don’t know.” She sighed. “I’d like to think that she meant that the knowledge of a good deed done would console you, but it’s Camille, so …”

“Are all vampires like that?” Tessa asked. “Cold like that?”

“Many of them have been alive a long time,” Charlotte said diplomatically. “They don’t see things the way we do.”

Tessa put her fingers to her aching temples. “Indeed, they don’t.”

Of all the things that bothered Will about vampires—the way they moved soundlessly, the low and inhuman timbre of their voices—it was the way they smelled that bothered him most. Or rather, the way they didn’t smell. All human beings smelled like something—sweat, soap, perfume—but vampires had no scent, like wax mannequins.

Ahead of him, Jem was holding the last of the doors that led from the Sanctuary to the outer foyer of the Institute. All these spaces had been deconsecrated so that vampires and others of their ilk could use them, but Camille could never come any farther into the Institute than that. Escorting her out was more than a courtesy. They were making sure she didn’t accidentally wander onto consecrated ground, which would be dangerous for everyone involved.

Camille brushed by Jem, hardly looking at him, and Will followed, pausing only long enough to mutter “She doesn’t smell like anything” to Jem under his breath.

Jem looked alarmed. “You’ve been smelling her?”

Camille, who was waiting by the next doorway for them, turned her head at this and smiled. “I can hear everything you say, you know,” she said. “It is true, vampires have no scent. It makes us better predators.”

“That, and excellent hearing,” Jem said, and let the door swing shut behind Will. They were standing in the small square entryway with Camille now, her hand on the knob of the front door as if she meant to hurry out, but there was nothing hurried in her expression as she looked them over.

“Look at you both,” she said, “all black and silver. You could be a vampire,” she said to Jem, “with your pallor, and your looks. And you,” she said to Will, “well, I don’t think anyone at de Quincey’s will doubt that you could be my human subjugate.”

Jem was looking at Camille, with that look that Will always thought could cut glass. He said:

“Why are you doing this, Lady Belcourt? This plan of yours, de Quincey, all of it—why?”

Camille smiled. She was beautiful, Will had to admit—but then, a lot of vampires were beautiful. Their beauty had always seemed to him like the beauty of pressed flowers—lovely, but dead. “Because the knowledge of what he was doing weighed on my conscience.”

Jem shook his head. “Perhaps you are the sort who would sacrifice yourself on the altar of principle, but I doubt it. Most of us do things for reasons that are more purely personal. For love, or for hate.”

“Or for revenge,” Will said. “After all, you’ve known about what was going on for a year now, and you only just came to us.”

“That was because of Miss Gray.”

“Yes, but that’s not all it is, is it?” Jem said. “Tessa is your opportunity, but your reason, your motive, is something else.” He cocked his head to the side. “Why do you hate de Quincey so much?”

“I don’t see what business it is of yours, little silver Shadowhunter,” Camille said, and her lips had drawn back from her teeth, leaving her fangs visible, like bits of ivory against the red of her lips. Will knew that vampires could show their fangs at will, but it was still unnerving. “Why does it matter what my motives are?”

Will filled in the answer for Jem, already knowing what the other boy had been thinking. “Because otherwise we can’t trust you. Perhaps you’re sending us into a trap. Charlotte wouldn’t want to believe it, but that doesn’t make it not possible.”

“Lead you into a trap?” Camille’s tone was mocking. “And incur the terrifying wrath of the Clave? Hardly likely!”

“Lady Belcourt,” said Jem, “whatever Charlotte might have promised you, if you want our help, you will answer the question.”