They reached the second landing, and Magnus padded off down the corridor, opening doors as he went and muttering to himself. Finally finding the correct room, he threw the door open and gestured for Will to follow him.
The bedroom of Woolsey Scott’s dead brother was dark and cold, and the air smelled of dust. Automatically Will fumbled for his witchlight, but Magnus waved a dismissing hand at him, blue fire sparking from his fingertips. A fire roared up suddenly in the grate, lighting the room. It was furnished, though everything had been draped with white cloths—the bed, the wardrobe and dressers. As Magnus stalked through the room, rolling up his shirtsleeves and gesturing with his hands, the furniture began to slide back from the center of the room. The bed swung around and lay flat against the wall; the chairs and bureaus and washstand flew into the corners of the room.
Will whistled. Magnus grinned. “Easily impressed,” Magnus said, though he sounded slightly out of breath. He knelt down in the now denuded center of the room and hastily drew a pentagram. In each point of the occult symbol, he scrawled a rune, though none were runes Will knew from the Gray Book. Magnus raised his arms and held them out over the star; he began to chant, and gashes opened up in his wrists, spilling blood into the pentagram’s center. Will tensed as the blood struck the floor and began to burn with an eerie blue glow. Magnus backed out of the pentagram, still chanting, reached into his pocket, and produced the demon’s tooth. As Will watched, Magnus tossed it into the now flaming center of the star.
For a moment nothing happened. Then, out of the burning heart of the fire, a dark shape began to take form. Magnus had stopped chanting; he stood, his narrowed eyes focused on the pentagram and what was happening within it, the gashes on his arms closing swiftly. There was little sound in the room, just the crackle of the fire and Will’s harsh breathing, loud in his own ears, as the dark shape grew in size—coalesced, and, finally, took a solid, recognizable shape.
It was the blue demon from the party, no longer dressed in evening wear. Its body was covered in overlapping blue scales, and a long yellowish tail with a stinger on the end switched back and forth behind it. The demon looked from Magnus to Will, its scarlet eyes narrowed.
“Who summons the demon Marbas?” it demanded in a voice that sounded as if its words were echoing from the bottom of a well.
Magnus jerked his chin toward the pentagram. The message was clear: This was Will’s business now.
Will took a step forward. “You don’t remember me?”
“I remember you,” the demon growled. “You chased me through the grounds of the Lightwood country house. You tore out one of my teeth.” It opened its mouth, showing the gap. “I tasted your blood.” Its voice was a hiss. “When I escape this pentagram, I will taste it again, Nephilim.”
“No.” Will stood his ground. “I’m asking you if you remember me.”
The demon was silent. Its eyes, dancing with fire, were unreadable.
“Five years ago,” said Will. “A box. A Pyxis. I opened it, and you emerged. We were in my father’s library. You attacked, but my sister fended you off with a seraph blade. Do you recollect me now?”
There was a long, long silence. Magnus kept his cat’s eyes fixed on the demon. There was an implied threat in them, one that Will couldn’t read. “Speak the truth,” Magnus said finally. “Or it will go badly for you, Marbas.”
The demon’s head swung toward Will. “You,” it said reluctantly. “You are that boy. Edmund Herondale’s son.”
Will sucked in a breath. He felt suddenly light-headed, as if he were going to pass out. He dug his nails into his palms, hard, gashing the skin, letting the pain clear his head. “You remember.”
“I had been trapped for twenty years in that thing,” Marbas snarled. “Of course I remember being freed. Imagine it, if you can, idiot mortal, years of blackness, darkness, no light or movement—and then the break, the opening. And the face of the man who imprisoned you hovering just above your gaze.”
“I am not the man who imprisoned you—”
“No. That was your father. But you look just like him to my eyes.” The demon smirked. “I remember your sister. Brave girl, fending me off with that blade she could hardly use.”
“She used it well enough to keep you away from us. That’s why you cursed us. Cursed me. Do you remember that?”
The demon chuckled. “‘All who love you will find only death. Their love will be their destruction. It may take moments, it may take years, but any who look upon you with love will die of it. And I shall begin it with her.’”
Will felt as if he were breathing fire. His whole chest burned. “Yes.”
The demon cocked its head to the side. “And you summoned me that we might reminisce about this shared event in our past?”
“I called you up, you blue-skinned bastard, to get you to take the curse off me. My sister—Ella—she died that night. I left my family to keep them safe. It’s been five years. It’s enough. Enough!”
“Do not try to engage my pity, mortal,” said Marbas. “I was twenty years tortured in that box. Perhaps you too should suffer for twenty years. Or two hundred—”
Will’s whole body tensed. Before he could fling himself toward the pentagram, Magnus said, in a calm tone, “Something about this story strikes me as odd, Marbas.”
The demon’s eyes flicked toward him. “And what is that?”
“A demon, upon being let out of a Pyxis, is usually at its weakest, having been starved for as long as it was imprisoned. Too weak to cast a curse as subtle and strong as the one you claim to have cast on Will.”
The demon hissed something in a language Will didn’t know, one of the more uncommon demon languages, not Cthonic or Purgatic. Magnus’s eyes narrowed.
“But she died,” Will said. “Marbas said my sister would die, and she did. That night.”
Magnus’s eyes were still fixed on the demon’s. Some kind of battle of wills was taking place silently, outside Will’s range of understanding. Finally Magnus said, softly, “Do you really wish to disobey me, Marbas? Do you wish to anger my father?”
Marbas spat a curse, and turned to Will. Its snout twitched. “The half-caste is correct. The curse was false. Your sister died because I struck her with my stinger.” It swished its yellowish tail back and forth, and Will remembered Ella knocked to the ground by that tail, the blade skittering from her hand. “There has never been a curse on you, Will Herondale. Not one put there by me.”
“No,” Will said softly. “No, it isn’t possible.” He felt as if a great storm were blowing through his head; he remembered Jem’s voice saying the wall is coming down, and he envisioned a great wall that had surrounded him, isolated him, for years, crumbling away into sand. He was free—and he was alone, and the icy wind cut through him like a knife. “No.” His voice had taken on a low, keening note. “Magnus . . .”
“Are you lying, Marbas?” Magnus snapped. “Do you swear on Baal that you are telling the truth?”
“I swear,” said Marbas, red eyes rolling. “What benefit would it be to me to lie?”
Will slid to his knees. His hands were locked across his stomach as if they were keeping his guts from spilling out. Five years, he thought. Five years wasted. He heard his family screaming and pounding on the doors of the Institute and himself ordering Charlotte to send them away. And they had never known why. They had lost a daughter and a son in a matter of days, and they had never known why. And the others—Henry and Charlotte and Jem—and Tessa—and the things he had done—