“I—” Kit realized he was grinning, and broke off. He’d always had a sarcastic edge to his tongue, never been someone to take a compliment gracefully, but it was as if there was something about Ty Blackthorn that reached into him and untied all the careful knots of protection holding him together. He wondered if that was what people meant when they said they felt undone.

Ty frowned as if he hadn’t noticed Kit’s stupid smile. “The problem is,” he said, “neither of us drive. We have no way of getting to the Market.”

“But you have an iPhone,” said Kit. “In fact, there’s several in the Institute. I’ve seen them.”

“Sure,” said Ty, “but—”

“I’m going to introduce you to a wonderful invention called Uber,” said Kit. “Your life will be changed, Ty Blackthorn.”

“Ah, Watson,” said Ty, shoving the clip into his pocket. “You may not yourself be luminous, but you are an extraordinary conductor of light.”

*

Diego had been surprised that Gladstone wanted to lock them in the library. He’d never thought of it as a particularly secure room. Once they were both inside, Diego stripped of his weapons and stele, and the solid oak door had been locked behind them, Diego began to realize the advantages the library had as a prison.

The walls were thick and there were no windows save for the massive glass ceiling many feet up. The sheer walls made it impossible to climb up and break it, and nothing in the room yielded a useful weapon—they could throw books, Diego supposed, or try to flip the tables, but he didn’t figure that would do much good.

He stalked over to where Kieran sat slumped at the foot of the massive tree that grew up out of the floor. If only it reached up high enough to get to the ceiling, Diego thought.

Kieran was hunched against the trunk. He had jammed the palms of his hands into his eyes, as if he could blind himself.

“Are you all right?” Diego said.

Kieran dropped his hands. “I am sorry.” He looked up at Diego, who could see the marks of Kieran’s palms against his cheekbones.

“It’s fine. You were injured. I can look for ways out by myself,” Diego said, deliberately misunderstanding him.

“No, I mean I am sorry,” Kieran choked out. “I cannot.”

“You cannot what?”

“Get away from it. I feel guilt like a curtain of thorns in which I am entangled. Every which way I turn I am pierced again.”

The pool makes you feel every hurt you have ever caused others. “We are none of us without guilt,” said Diego, and he thought of his family, of Cristina. “Every one of us has hurt another, inadvertently or not.”

“You do not understand.” Kieran was shaking his head. A lock of hair fell across his forehead, silver darkening to blue. “When I was in the Hunt, I was a straw floating in wind or water. All I could do was clutch at other straws. I believed I had no effect in the world. That I mattered so little I could neither help nor harm.” He tensed his hands into fists. “Now I have felt the pain that was Emma’s and the sorrow that was Mark’s, the pain of everyone I harmed in the Hunt, even Erec’s pain as he died. But how could I have been the person who caused such pain when I am someone whose actions are written in water?”

His eyes, black and silver, were haunted. Diego said, “Kieran. You have not only caused pain in this world. It is just that the pool does not show good, only hurt.”

“How do you know?” Kieran cried. “We are but barely acquainted, you and I—”

“Because of Cristina,” said Diego. “Cristina had faith in you. True faith, unblemished and unbroken. Why do you think I agreed to hide you here? Because she believed you were good, and I believed in her.”

He stopped before he could say too much, but Kieran had already winced at the mention of Cristina. His next question puzzled Diego. “How can I face her again?” he said.

“Do you care that much what she thinks?” Diego said. It hadn’t occurred to him that Kieran might. Surely he couldn’t know Cristina that well.

“More than you might imagine or guess,” Kieran said. “How did you ever face her again, after you engaged yourself to Zara and broke her heart?”

“Really?” Diego was stung. “We need to bring this up now?”

Kieran looked at him with wild eyes. Diego sighed. “Yes, I disappointed Cristina and I lost her regard—you must understand what that is like. To have let down someone you loved. To have disappointed yourself.”

“Maybe not exactly,” said Kieran, with a shadow of his old wryness. “Nobody calls me Perfect Kieran.”

“I don’t call myself Perfect Diego!” Diego protested, feeling that the conversation had degenerated. “Nobody would call themselves that!”

There was a noise at the door. Both of them turned, poised for danger, but as it swung open Diego was shocked to see Divya on the threshold.

She looked as if she’d been in a fight. Scratched and bloody, she held up the key. “I got it from Gladstone in the infirmary chaos,” she said. “I doubt we have much time before he notices it’s gone.”

Diego stalked past her and opened the library door a crack. The corridor was empty. “What’s happening? Where’s Rayan?”

“Trying to see what the others know, the ones who came from Alicante and aren’t in the Cohort. Everyone’s steles have been confiscated. Zara Portaled back to Idris right after you took Kieran away. And Gladstone’s in the infirmary with Samantha,” said Divya. “She won’t stop screaming.” She bit her lip. “It’s really bad.”

Kieran had risen to his feet, though he was still using the tree to support himself. “You two should run,” he said. “Get out of here. It’s me they want, and you have put yourselves in enough danger on my account.”

Divya gave him a wry look. “By the Angel, he’s all self-sacrificing now he fell in that pool. Faerie, you haven’t caused me any harm. We’re fine.”

“I made you worry and feel fear,” said Kieran, gazing at her with a look both haunting and haunted. “You were afraid of what might happen to you and the others, retaliation for hiding me. You feared for Rayan.” He glanced at Diego. “And you—”

“No.” Diego held up a hand. “I don’t want to hear about my feelings.”

“Said every man ever,” Divya quipped, but her eyes were overly bright. “Look, there’s more I need to tell you. And you should both hear it. I heard Zara laughing with Gladstone in the infirmary before they brought Samantha in. The Inquisitor sent two Shadowhunters on a suicide mission to Faerie to find the Black Volume.”

“Jace and Clary?” said Diego, puzzled. “That’s not a suicide mission.”

“Not them. Emma and Julian Blackthorn. They left yesterday.”

“They would never agree to a suicide mission,” said Kieran. “Julian would not leave his brothers and sisters. Never.”

“They don’t know it’s a suicide mission—Dearborn sent someone to follow them and kill them before they can come back.”

“That’s against the Law.” It was all Diego could think of to say, and he immediately felt ridiculous.

“Horace Dearborn doesn’t care about your Laws,” said Kieran. His cheeks were flushed darkly with color. “He cares for nothing beyond furthering his own purpose. To him a Nephilim who doesn’t agree with him is no better than a Downworlder. They are all vermin to be destroyed.”

“Kieran’s right,” said Divya. “He’s the Inquisitor, Diego. He’s going to change all the Laws—change them so he can do whatever he wants.”

“We must go,” said Kieran. “There is not a moment to lose. We must tell the Blackthorns—Mark and Cristina—”

“All the exits are guarded,” said Divya. “I’m not saying it’s impossible, but we’re going to need Rayan and Gen and the others. We can’t fight the Cohort alone. Especially not without steles. We’ll need to plan—”

“We do not have time to plan—” Kieran began.

Diego thought suddenly of Cristina, of the way she’d written about Kieran in her letter asking Diego to hide him. The fascination she’d had with faeries even when she was a little girl, the way she’d cried when the Cold Peace was passed, telling Diego over and over the faeries were good, their powers part of the blessed magic of the world.

“Kieran,” Diego said sharply. “You are a prince of Faerie. Be a prince of Faerie.”

Kieran gave him a wild, dark look. His breath was ragged. Divya glanced at Diego as if to say what are you doing? just as Kieran reached up to seize a branch of the tree.

He closed his black and silver eyes. His face was a pale mask. His jaw tightened even as the leaves on the tree began to rustle, as if in a high wind. It was as if the tree were calling out.

“What’s happening?” whispered Divya.

Light crackled up and down the tree—not lightning, but pure bright sparks. It circled Kieran as if he were outlined in gold paint. His hair had turned an odd gold-green, something Diego had never seen before.

“Kieran—” Diego started.

Kieran threw his hands up. His eyes were still closed; words poured from his mouth, a language Diego had never heard. He wished Cristina were here. Cristina could translate. Kieran was shouting; Diego thought he heard the word “Windspear” repeated.

Windspear? thought Diego. Isn’t that—?

“There are people coming!” Divya cried. She ran to the door of the library, slammed it closed, and locked it, but she was shaking her head. “There are way too many of them. Diego—”