"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?"

"Nothing in this world," said Dolores. "A blade of Heaven or Hell might do it. The sword of the Archangel Michael, that Joshua fought with at Jericho, for it is infused with heavenly fire. And there are blades forged in the blackness of the Pit that might aid you, though how one might be obtained, I do not know."

"And we would be prevented from telling you by the Law if we did know," said Cleophas with asperity. "You understand, of course, that we will also have to tell the Clave about this visit of yours-"

"What about Joshua's sword?" interrupted Isabelle. "Can you get that? Or can we?"

"Only an angel can gift you that sword," said Dolores. "And to summon an angel is to be blasted with heavenly fire."

"But Raziel-," Isabelle began.

Cleophas's lips thinned into a straight line. "Raziel left us the Mortal Instruments that he might be called upon in a time of direst need. That one chance was wasted when Valentine summoned him. We shall never be able to compel his might again. It was a crime to use the Instruments in that manner. The only reason that Clarissa Morgenstern escapes culpability is that it was her father who summoned him, not herself."

"My husband also summoned another angel," said Jocelyn. Her voice was quiet. "The angel Ithuriel. He kept him imprisoned for many years."

Both Sisters hesitated before Dolores spoke. "It is the bleakest of crimes to entrap an angel," she said. "The Clave could never approve it. Even if you could summon one, you could never force it to do your bidding. There is no spell for that. You could never get an angel to give you the archangel's sword; you can take by force from an angel, but there is no greater crime. Better that your Jonathan die than that an angel be so besmirched."

At that, Isabelle, whose temper had been rising, exploded. "That's the problem with you-all of you, the Iron Sisters and the Silent Brothers. Whatever they do to change you from Shadowhunters to what you are, it takes all the feelings out of you. We might be part angel, but we're part human, too. You don't understand love, or the things people do for love, or family-"

The flame leaped in Dolores's orange eyes. "I had a family," she said. "A husband and children, all murdered by demons. There was nothing left to me. I had always had a skill with shaping things with my hands, so I became an Iron Sister. The peace it has brought me is peace I think I would never have found elsewhere. It is for that reason I chose the name Dolores, "sorrow." So do not presume to tell us what we do or do not know about pain, or humanity."

"You don't know anything," Isabelle snapped. "You're as hard as demon-stone. No wonder you surround yourselves with it."

"Fire tempers gold, Isabelle Lightwood," said Cleophas.

"Oh, shut up," Isabelle said. "You've been very unhelpful, both of you."

She turned on the heel of her boot, spun away, and stalked back across the bridge, barely taking note of where the knives turned the path into a death trap, letting her body's training guide her. She reached the other side and strode through the gates; only when she was outside them did she break down. Kneeling among the moss and volcanic rocks, under the great gray sky, she let herself shake silently, though no tears came.

It seemed ages before she heard a soft step beside her, and Jocelyn knelt and put her arms around her. Oddly, Isabelle found that she didn't mind. Though she had never much liked Jocelyn, there was something so universally motherly in her touch that Isabelle leaned into it, almost against her own will.

"Do you want to know what they said, after you left?" Jocelyn asked, after Isabelle's trembling had slowed.

"I'm sure something about how I'm a disgrace to Shadowhunters everywhere, et cetera."

"Actually, Cleophas said you'd make an excellent Iron Sister, and if you were ever interested to let them know." Jocelyn's hand stroked her hair lightly.

Despite everything, Isabelle choked back a laugh. She looked up at Jocelyn. "Tell me," she said.

Jocelyn's hand stop moving. "Tell you what?"

"Who it was. That my father had the affair with. You don't understand. Every time I see a woman my mother's age, I wonder if it was her. Luke's sister. The Consul. You-"

Jocelyn sighed. "It was Annamarie Highsmith. She died in Valentine's attack on Alicante. I doubt you ever knew her."

Isabelle's mouth opened, then closed again. "I've never even heard her name before."

"Good." Jocelyn tucked a lock of Isabelle's hair back. "Do you feel any better, now that you know?"

"Sure," Isabelle lied, staring down at the ground. "I feel a lot better."

After lunch Clary had returned to the downstairs bedroom with the excuse that she was exhausted. With the door firmly closed she had tried contacting Simon again, though she realized, given the time difference between where she was now-Italy-and New York, there was every chance he was asleep. At least she prayed he was asleep. It was far preferable to hope for that than to consider the possibility that the rings might not work.

She had been in the bedroom for only about half an hour when a knock sounded at the door. She called, "Come in," moving to lean back on her hands, her fingers curled in as if she could hide the ring.

The door swung open slowly, and Jace looked down at her from the doorway. She remembered another night, summer heat, a knock on her door. Jace. Clean, in jeans and a gray shirt, his washed hair a halo of damp gold. The bruises on his face were already fading from purple to faint gray, and his hands were behind his back.

"Hey," he said. His hands were in plain sight now, and he was wearing a soft-looking sweater the color of bronze that brought out the gold in his eyes. There were no bruises on his face, and the shadows she had almost grown used to seeing under his eyes were gone.

Is he happy like this? Really happy? And if he is, what are you saving him from?

Clary pushed away the tiny voice in her head and forced a smile. "What's up?"

He grinned. It was a wicked grin, the kind that made the blood in Clary's veins run a little faster. "You want to go on a date?"

Caught off guard, she stammered. "A wh-what?"

"A date," Jace repeated. "Often 'a boring thing you have to memorize in history class,' but in this case, 'an offer of an evening of blisteringly white-hot romance with yours truly.'"

"Really?" Clary was not sure what to make of this. "Blisteringly white-hot?"

"It's me," said Jace. "Watching me play Scrabble is enough to make most women swoon. Imagine if I actually put in some effort."

Clary sat up and looked down at herself. Jeans, silky green top. She thought about the cosmetics in that odd shrine-like bedroom. She couldn't help it; she was wishing for a little lip gloss.