"Very well." She stretched, languorously, like a cat. "It was many years ago, when Magnus and I were lovers. We were in bed together, after quite a passionate evening." She saw him flinch, and grinned. "You know how it is with pillow talk. One reveals one's weaknesses. Magnus spoke to me of a spell that existed, one that might be undertaken to rid a warlock of their immortality."
"So why don't I just find out what the spell is and do it?" Alec's voice rose and cracked. "Why do I need you?"
"First, because you're a Shadowhunter; you've no idea how to work a spell," she said calmly. "Second, because if you do it, he'll know it was you. If I do it, he will assume it is revenge. Spite on my part. And I do not care what Magnus thinks. But you do."
Alec looked at her steadily. "And you're going to do this for me as a favor?"
She laughed, like tinkling bells. "Of course not," she said. "You do a favor for me, and I will do one for you. That is how these matters are conducted."
Alec's hand tightened around the witchlight rune-stone until the edges cut into his hand. "And what favor do you want from me?"
"It's very simple," she said. "I want you to kill Raphael Santiago."
The bridge that crossed the crevasse surrounding the Adamant Citadel was lined with knives. They were sunk, point upward, at random intervals along the path, so that it was possible to cross the bridge only very slowly, by picking your way with dexterity. Isabelle had little trouble but was surprised to see how lightly Jocelyn, who hadn't been an active Shadowhunter in fifteen years, made her way.
By the time Isabelle had reached the opposite side of the bridge, her dexteritas rune had vanished into her skin, leaving a faint white mark behind. Jocelyn was only a step behind her, and as aggravating as Isabelle found Clary's mother, she was glad in a moment, when Jocelyn raised her hand and a witchlight rune-stone blazed forth, illuminating the space they stood in.
The walls were hewn from white-silver adamas, so that a dim light seemed to glow from within them. The floor was demon-stone as well, and carved into the center of it was a black circle. Inside the circle the symbol of the Iron Sisters was carved-a heart punctured through and through by a blade.
Whispering voices made Isabelle tear her gaze from the floor and look up. A shadow had appeared inside one of the smooth white walls-a shadow growing ever clearer, ever closer. Suddenly a portion of the wall slid back and a woman stepped out.
She wore a long, loose white gown, bound tightly at the wrists and under her breasts with silver-white cord-demon wire. Her face was both unwrinkled and ancient. She could have been any age. Her hair was long and dark, hanging in a thick braid down her back. Across her eyes and temples was an intricately curlicued tattooed mask, encircling both her eyes, which were the orange color of leaping flames.
"Who calls on the Iron Sisters?" she said. "Speak your names."
Isabelle looked toward Jocelyn, who gestured that she should speak first. She cleared her throat. "I am Isabelle Light-wood, and this is Jocelyn Fr-Fairchild. We have come to ask your help."
"Jocelyn Morgenstern," said the woman. "Born Fairchild, but you cannot so easily erase the taint of Valentine from your past. Have you not turned your back on the Clave?"
"It is true," said Jocelyn. "I am outcast. But Isabelle is a daughter of the Clave. Her mother-"
"Runs the New York Institute," said the woman. "We are remote here but not without sources of information; I am no fool. My name is Sister Cleophas, and I am a Maker. I shape the adamas for the other sisters to carve. I recognize that whip you wind so cunningly around your wrist." She indicated Isabelle. "As for that bauble about your throat-"
"If you know so much," said Jocelyn, as Isabelle's hand crept to the ruby at her neck, "then do you know why we are here? Why we have come to you?"
Sister Cleophas's eyelids lowered and she smiled slowly. "Unlike our speechless brethren, we cannot read minds here in the Fortress. Therefore we rely upon a network of information, most of it very reliable. I assume this visit has something to do with the situation involving Jace Lightwood-as his sister is here-and your son, Jonathan Morgenstern."
"We have a conundrum," said Jocelyn. "Jonathan Morgenstern plots against the Clave, like his father. The Clave has issued a death warrant against him. But Jace-Jonathan Lightwood-is very much loved by his family, who have done no wrong, and by my daughter. The conundrum is that Jace and Jonathan are bound, by very ancient blood magic."
"Blood magic? What sort of blood magic?"
Jocelyn took Magnus's folded notes from the pocket of her gear and handed them over. Cleophas studied them with her intent fiery gaze. Isabelle saw with a start that the fingers of her hands were very long-not elegantly long but grotesquely so, as if the bones had been stretched so that each hand resembled an albino spider. Her nails were filed to points, each tipped with electrum.
She shook her head. "The Sisters have little to do with blood magic." The flame color of her eyes seemed to leap and then dim, and a moment later another shadow appeared behind the frosted-glass surface of the adamas wall. This time Isabelle watched more closely as a second Iron Sister stepped through. It was like watching someone emerge from a haze of white smoke.
"Sister Dolores," said Cleophas, handing Magnus's notes to the new arrival. She looked much like Cleophas-the same tall narrow form, the same white dress, the same long hair, though in this case her hair was gray, and bound at the ends of her two braids with gold wire. Despite her gray hair, her face was lineless, her fire-colored eyes bright. "Can you make sense of this?"
Dolores glanced over the pages briefly. "A twinning spell," she said. "Much like our own parabatai ceremony, but its alliance is demonic."
"What makes it demonic?" Isabelle demanded. "If the parabatai spell is harmless-"
"Is it?" said Cleophas, but Dolores shot her a quelling look.
"The parabatai ritual binds two individuals but leaves their wills free," Dolores explained. "This binds two but makes one subordinate to the other. What the primary of the two believes, the other will believe; what the first one wants, the second will want. It essentially removes the free will of the secondary partner in the spell, and that is why it is demonic. For free will is what makes us Heaven's creatures."
"It also seems to mean that when one is wounded, the other is wounded," said Jocelyn. "Might we presume the same about death?"
"Yes. Neither will survive the death of the other. This again is not part of our parabatai ritual, for it is too cruel."
"Our question to you is this," said Jocelyn. "Is there any weapon forged, or that you might create, that could harm one but not the other? Or that might cut them apart?
Sister Dolores looked down at the notes, then handed them to Jocelyn. Her hands, like those of her colleague, were long and thin and as white as floss. "No weapon we have forged or could ever forge might do that."
Isabelle's hand tightened at her side, her nails cutting into her palm. "You mean there's nothing?"