Brother Enoch loomed over him, glowering, as Jace bent down with slow precision to do up the laces on his boots. He was sitting on the edge of the infirmary bed, one of a line of white-sheeted cots that ran the length of the long room. Many of the other cots were taken up with Shadowhunter warriors, recovering from the battle at the Citadel. Silent Brothers moved among the beds like ghostly nurses. The air smelled of herbs and strange poultices.

You should take another night to rest, at least. Your body is spent, and the heavenly fire still burns within you.

Finished with his boots, Jace looked up. The arched ceiling above was painted with an interlaced design of healing runes in silver and blue. He’d been staring up at it for what felt like weeks, though he knew it had been only a night. The Silent Brothers, keeping all visitors away, had hovered over him with healing runes and poultices. They had also run tests on him, taking blood, hair, even eyelashes—touching him with a series of blades pressed to his skin: gold, silver, steel, rowan wood. He felt fine. He had a strong feeling that keeping him in the Basilias was more about studying the heavenly fire than it was about healing him.

“I want to see Brother Zachariah,” he said.

He is well. You need not worry yourself about him.

“I want to see him,” he said. “I nearly killed him at the Citadel—”

That was not you. That was the heavenly fire. And it did anything but harm him.

Jace blinked at the odd choice of words. “He said when I met him that he believes that a debt is owed the Herondales. I’m a Herondale. He’d want to see me.”

And then you intend to depart the Basilias?

Jace stood up. “There’s nothing wrong with me. I don’t need to be in the infirmary. Surely you could be using your resources more fruitfully on the actually wounded.” He caught his jacket off a hook by the bed. “Look, you can either bring me to Brother Zachariah or I can wander around yelling for him until he turns up.”

You are a great deal of trouble, Jace Herondale.

“So I’ve been told,” Jace said.

There were arched windows between the beds; they cast wide spokes of light across the marble floor. The day was beginning to dim: Jace had woken in the early afternoon, with a Silent Brother by his bed. He’d jerked upright, demanding to know where Clary was, as recollections of the night before poured through him: he recalled the pain when Sebastian had stabbed him, recalled the fire blazing up the blade, recalled Zachariah burning. Clary’s arms around him, her hair falling down around them both, the cessation of pain that had come with darkness. And then—nothing.

After the Brothers had reassured him that Clary was all right, safe at Amatis’s, he’d asked after Zachariah, whether the fire had harmed him, but had received only irritatingly vague answers.

Now he followed Enoch out of the infirmary hall and into a narrower, white-plastered corridor. Doors opened off the corridor. As they passed one, Jace caught a quick glimpse of a writhing body tied to a bed, and heard the sound of screaming and cursing. A Silent Brother stood over a thrashing man dressed in the remnants of red gear. Blood spattered the white wall behind them.

Amalric Kriegsmesser, said Brother Enoch without turning his head. One of Sebastian’s Endarkened. As you know, we have been attempting to reverse the spell of the Infernal Cup.

Jace swallowed. There didn’t seem anything to say. He had seen the ritual of the Infernal Cup performed. In his heart of hearts he didn’t believe the spell could be reversed. It created too fundamental a change. But then neither had he ever imagined that a Silent Brother could be as human as Brother Zachariah had always seemed. Was that why he was so determined to see him? He remembered what Clary had told him Brother Zachariah had said once, when she’d asked him if he’d ever loved anyone enough to die for them:

Two people. There are memories that time does not erase. Ask your friend Magnus Bane, if you do not believe me. Forever does not make loss forgettable, only bearable.

There had been something about those words, something that spoke of a sorrow and a sort of memory that Jace did not associate with the Brothers. They had been a presence in his life since he was ten: pale silent statues who brought healing, who kept secrets, who did not love or desire or grow or die but only were. But Brother Zachariah was different.

We are here. Brother Enoch had paused in front of an unremarkable white-painted door. He lifted a broad hand and knocked. There was a sound from inside, as of a chair scraping back, and then a male voice:

“Come in.”

Brother Enoch swung the door open and ushered Jace inside. The windows were west-facing, and it was very bright in the room, the light of the sun as it went down painting the walls with pale fire. There was a figure at the window: a silhouette, slender, not in the robes of a Brother—Jace turned to look at Brother Enoch in surprise, but the Silent Brother had already left, closing the door behind him.

“Where’s Brother Zachariah?” Jace said.

“I’m right here.” A quiet voice, soft, a little out of tune, like a piano that hadn’t been played in years. The figure had turned from the window. Jace found himself looking at a boy only a few years older than himself. Dark hair, a sharp delicate face, eyes that seemed young and old at the same time. The runes of the Brothers marked his high cheekbones, and as the boy turned, Jace saw the pale edge of a faded rune at the side of his throat.

A parabatai. Like he was. And Jace knew too what that faded rune meant: a parabatai whose other half was dead. He felt his sympathy leap toward Brother Zachariah, as he imagined himself without Alec, with only that faded rune to remind him where once he had been bonded to someone who knew all the best and worst parts of his soul.

“Jace Herondale,” said the boy. “Once more a Herondale is the bringer of my deliverance. I should have anticipated.”

“I didn’t—that’s not—” Jace was too stunned to think of anything clever to say. “It’s not possible. Once you’re a Silent Brother, you can’t change back. You—I don’t understand.”

The boy—Zachariah, Jace supposed, though not a Brother anymore—smiled. It was a heartbreakingly vulnerable smile, young and gentle. “I am not sure I entirely understand either,” he said. “But I was never an ordinary Silent Brother. I was brought into the life because there was a dark magic upon me. I had no other way to save myself.” He looked down at his hands, the unlined hands of a boy, smooth the way few Shadowhunters’ hands were smooth. The Brothers could fight as warriors, but rarely did. “I left everything I knew and everything I loved. Didn’t leave it entirely, perhaps, but erected a wall of glass between myself and the life I’d had before. I could see it, but I could not touch, could not be a part of it. I began to forget what it was like to be an ordinary human.”

“We’re not ordinary humans.”

Zachariah looked up. “Oh, we tell ourselves that,” he said. “But I have made a study of Shadowhunters now, over the past century, and let me tell you that we are more human than most human beings. When our hearts break, they break into shards that cannot be easily fit back together. I envy mundanes their resilience sometimes.”

“More than a century old? You seem pretty . . . resilient to me.”

“I thought I would be a Silent Brother forever. We—they don’t die, you know; they fade after many years. Stop speaking, stop moving. Eventually they are entombed alive. I thought that would be my fate. But when I touched you with my runed hand, when you were wounded, I absorbed the heavenly fire in your veins. It burned away the darkness in my blood. I became again the person I was before I took my vows. Before even that. I became what I have always wanted to be.”