“My master wants demon energies, and demon energies he shall have,” said Nate pompously. “Nor will he forget that I am the one who provided them for him.”
Jem shook his head. “And what will he give you then? What did he give you to betray your sister? Thirty pieces of silver?”
Nate’s face twisted, and for a moment Jem thought he could see through the blandly handsome mask to what was really underneath—something malignant and repellent that made Jem want to turn away and retch. “That thing,” he said, “is not my sister.”
“It is hard to believe, isn’t it,” said Jem, making no effort to hide his loathing, “that you and Tessa share anything at all, even a single drop of blood. She is so much finer than you.”
Nathaniel’s eyes narrowed. “She is not my concern. She belongs to Mortmain.”
“I don’t know what Mortmain has promised you,” Jem said, “but I can promise you that if you hurt Jessamine or Sophie—and if you take the Pyxis from these premises—the Clave will hunt you. And find you. And kill you.”
Nathaniel shook his head slowly. “You don’t understand,” he said. “None of the Nephilim understand. The most you can offer is to let me live. But the Magister can promise me that I won’t ever die.” He turned to the clockwork creature on his left, the one not holding the Pyxis. “Kill him,” he said.
The automaton sprang toward Jem. It was faster by far than the creatures Jem had faced on Blackfriars Bridge. He barely had time to flip the catch that released the blade at the end of his cane and raise it, before the thing was on him. The creature squealed like a braking train when Jem drove the blade directly into its chest and sawed it from side to side, tearing the metal wide open. The creature spun away, spraying a Catherine wheel of red sparks.
Nate, caught by the spray of fire, yelled and jumped back, beating at the sparks burning holes into his clothes. Jem took the opportunity to leap up two of the steps and slam Nate across the back with the flat of his blade, knocking him to his knees. Nate twisted around to look for his clockwork protector, but it was staggering from side to side across the steps, sparks fountaining from its chest; it seemed evident that Jem had severed one of its central mechanisms. The automaton holding the Pyxis stood stock-still; clearly Nate was not its first priority.
“Drop them!” Nate cried to the clockwork creatures holding Sophie and Jessamine. “Kill the Shadowhunter! Kill him, do you hear?”
Jessamine and Sophie, released, tumbled to the ground, both gasping but clearly still alive. Jem’s relief was short-lived, though, as the second pair of automatons lurched toward him, moving with incredible speed. He slashed out at one with his cane. It leaped back, out of range, and the other raised a hand—not a hand, really, more a square block of metal, its side edged with ragged teeth like a saw—
A yell came from behind Jem, and Henry charged past him, wielding a massive broadsword. He swung it hard, slashing through the automaton’s raised arm and sending its hand flying. It skidded across the cobblestones, sparking and hissing, before bursting into flames.
“Jem!” It was Charlotte’s voice, raised in warning. Jem spun, and saw the other automaton reaching for him from behind. He drove his blade into the creature’s throat, sawing at the copper tubes inside, while Charlotte slashed at its knees with her whip. With a high whine, it collapsed to the ground, legs severed. Charlotte, her pale face set, brought the whip down again, while Jem turned to see that Henry, his ginger hair pasted to his forehead with sweat, was lowering his broadsword. The automaton he had attacked was now a heap of scrap metal on the ground.
In fact, bits of clockwork were scattered across the courtyard, some of it still burning, like a field of fallen stars. Jessamine and Sophie were clinging to each other; Jessamine supporting the other girl, whose throat was necklaced with dark bruises. Jessamine met Jem’s eyes across the steps. He thought it might have been the first time she’d really ever looked like she was glad to see him.
“He’s gone,” she said. “Nathaniel. He vanished with that creature—and the Pyxis.”
“I don’t understand.” Charlotte’s bloodied face was a mask of shock. “Tessa’s brother …”
“Everything he said to us was a lie,” said Jessamine. “The whole business with sending you off after the vampires was a diversion.”
“Dear God,” said Charlotte. “So de Quincey wasn’t lying—” She shook her head, as if to clear it of cobwebs. “When we reached his house in Chelsea, we found him there with just a few vampires, no more than six or seven—certainly not the hundred Nathaniel had warned about, and no clockwork creatures that anyone could find. Benedict slew de Quincey, but not before the vampire laughed at us for calling him the Magister—said we had let Mortmain make fools of us. Mortmain. And I’d thought he was just—just a mundane.”
Henry sank down on the top step, his broad sword clanking. “This is a disaster.”
“Will,” Charlotte said dazedly, as if in a dream. “And Tessa. Where are they?”
“Tessa’s in the Sanctuary. With Mortmain. Will—” Jessamine shook her head. “I didn’t realize he was here.”
“He’s inside,” Jem said, raising his gaze to the Institute. He remembered his poison-racked dream—the Institute in flames, a haze of smoke over London, and great clockwork creatures striding to and fro among the buildings like monstrous spiders. “He would have gone after Tessa.”
Mortmain’s face had drained of blood. “What are you doing?” he demanded, striding toward her.
Tessa set the tip of the blade to her chest and pushed. The pain was sharp, sudden. Blood bloomed on the bosom of her dress. “Don’t come any closer.”
Mortmain stopped, his face contorted with fury. “What makes you think I care if you live or die, Miss Gray?”
“As you said, you made me,” said Tessa. “For whatever reason, you desired that I exist. You valued me enough that you would not have wanted the Dark Sisters to harm me in any permanent way. Somehow, I am significant to you. Oh, not my self, of course. My power. That is what matters to you.” She could feel blood, warm and wet, trickling down her skin, but the pain was nothing compared to her satisfaction at seeing the look of fear on Mortmain’s face.
He spoke through gritted teeth. “What is it you want from me?”
“No. What is it you want from me? Tell me. Tell me why you created me. Tell me who my true parents are. Was my mother really my mother? My father, my father?”
Mortmain’s smile was twisted. “You are asking the wrong questions, Miss Gray.”
“Why am I … what I am, and Nate is only human? Why is he not like me?”
“Nathaniel is only your half brother. He is nothing more than a human being, and not a very good example of that. Do not mourn that you are not more like him.”
“Then …” Tessa paused. Her heart was racing. “My mother could not have been a demon,” she said quietly. “Or anything supernatural, because Aunt Harriet was her sister, and she was only human. So it must have been my father. My father was a demon?”
Mortmain grinned, a sudden ugly grin. “Put down the knife and I will give you your answers. Perhaps we can even summon up the thing that fathered you, if you are so desperate to meet him—or should I say ‘it’?”