They were back in the entry hall of the Institute, and Tian was about to continue speaking when there was a sudden loud knock at the front doors. Tian looked sharply at the doors, then went to answer the knock, his brow furrowed.

“What’s wrong?” said Alec.

“You can’t knock on this door,” Tian said. “It’s half a meter thick. No one could knock hard enough.”

He pulled the door open and behind it, in the glare of the morning, was Magnus. He was doubled over, hands on his knees, panting, as though he’d been running hard.

“Magnus!” Alec started toward him.

Magnus looked wild-eyed, not like himself at all. He looked around at the group, then at Tian. “You must be Tian,” he said. “I’m Magnus Bane, good to meet you. All of you,” he added, “get out here and bring weapons. Now.”

* * *

ALEC FOLLOWED MAGNUS THROUGH THE doors. Behind him, Isabelle gasped.

Black curtains of shadow hung from the sky under what appeared to be a small, low-hanging storm cloud. There was no rain, though thunder rumbled. The area under the cloud was dark as night, and out of the boiling fog at the bottom of the cloud tumbled demons, dozens of them.

In the center of the rain of falling demons, a hundred feet above the ground, Shinyun floated, her hands raised. Light glowed around her, crimson and rippling.

“So, a few things,” said Magnus.

Tian emerged from the Institute, now holding something on a silver cord, which he whipped around beside him. “Who is that?”

“That is a very bad warlock who doesn’t like me,” said Magnus. “That’s the first thing. The second thing is, I’m not a hundred percent sure, but I think she may be in command of some demons.”

The demons who landed were rolling and coalescing into their various different forms. There were creatures that seemed made of the cloud bank itself, with cold, bone-white eyes. There were more of the snake demons that they had fought in the faerie’s apartment, and grinning skeletons.

Alec had come up beside Magnus and was sticking close to him. “How did she find us?”

“She found me,” said Magnus. “At the hotel.”

“How?” said Clary.

He rolled his eyes. “She has spies everywhere, apparently.”

“She attacked you?” said Jace.

“Yes, but then I left the hotel to come to the Institute and she showed up when I was halfway here and attacked me again, with demons this time.”

“Does that mean she stabbed you with the thorn again?” Alec said in alarm.

“There’s no time to go into that—”

Alec turned to face Magnus and grabbed him by the shoulders. “Did she stab you again?” he said again, more intently.

Magnus said, “Yes.”

It was like being stabbed himself. Alec closed his eyes.

“And it gets worse. But we really don’t have time for that yet. Right now we need to deal with her little army. They followed me here.”

“You led her to us?” Simon looked surprised.

“Well,” said Magnus in irritation, “I didn’t think I could handle her and all the demons by myself. What would you have suggested I do?”

Alec didn’t say anything. Normally, Magnus would have been able to neutralize Shinyun easily; he was a much more powerful warlock than her. Either she had grown more powerful or Magnus had become weaker. Or both. And now he’d been wounded again.

He drew his bow and fired a couple of arrows at the balls of fog; they stuck, so there was something solid in there. “Tian!” he called over. “Are these your locals? What am I shooting at?”

“The snakes are Xiangliu—do you not have them in America?” There was a flash, and the rope Tian was whirling suddenly burst forward, at an angle, and Alec saw that at the end of the rope was a diamond-shaped blade of adamas, which lopped the head off one of said Xiangliu. “The clouds are Ala, they’re mostly annoying.”

“Oh man,” said Isabelle, running to Tian, a slender staff in her hand. “What is that weapon? It’s awesome.”

Tian looked pleased. “Rope dart.” Expertly he spun the returning rope around his body, catching it near the blade to regain control.

“I want one,” said Isabelle. She whipped the end of the staff and a long curved blade, like a scimitar, unfolded and snapped into place at its end.

Simon had dropped his bow and drawn two seraph blades, which glowed in his hands like beacons in the unnatural dark. “Is that a guisarme?” he called to Isabelle.

Isabelle impaled a skeleton on the end of the weapon, then whipped it around and impaled a second skeleton before the first had even fallen. “It’s a glaive,” she said, with a wicked grin at Simon.

“God, I love you,” said Simon.

“Can someone throw some water on those two?” said Magnus. “Look, I’m sorry for bringing her here. I didn’t know what to do. Shinyun—I’m going to go and try to talk to her.”

“Can you fly up to where she is?” said Alec.

“Yes, but I’m going to need help if I don’t want to get knocked out of the sky.”

“We’ll keep everything else off you,” said Alec.

“I’m going to engage with the skeletons,” said Simon.

“I’m already engaged with the skeletons,” Isabelle said. She looked Simon up and down, concern showing through her battle-ready expression. “You got this?”

“I,” said Simon, “may only have been a Shadowhunter for a short time, but I have been preparing my whole life to fight skeleton warriors. I got this.”

Jace had disappeared. Alec cast his eyes over the swarm of demons and knocked an Ala out of the sky with two quick arrows. He soon caught sight of Jace, who was taking high leaps into the air, much higher than any mundane could, and whipping his flail into anything near him. Tian’s rope dart was making the Xiangliu dance and dodge to stay away from its unpredictable arcs, and as Alec laid down more arrow fire, he noted that Clary had placed herself so that the disoriented Xiangliu dodged away from Tian and directly into her seraph blades.

Behind Alec, sparks flew from Magnus’s fingers toward the ground, and he rose into the air toward Shinyun. Alec watched him, bow at the ready. There was something different about the sparks—they seemed… sharper? And there was an odd haze over the whole battle, like looking through a hot fire.

Around Alec the five other Shadowhunters laid waste to the demons on the ground. Alec kept his eyes on Magnus, knocking the cloud demons away with a well-placed arrow if they drifted toward him.

“Alec, behind you,” Simon yelled, and Alec whirled just in time to see a surprised-looking Xiangliu shatter its way out of existence. Tian’s rope dart hovered a few inches in front of Alec’s face, then whipped away. Alec looked over at Tian, who winked.

Alec returned his gaze to Magnus.

* * *

MAGNUS FLEW TOWARD SHINYUN AND wondered if she’d try to blow him out of the sky. He kept his gaze on her; he had to trust Alec to keep his path clear. He did trust Alec to keep his path clear.

“Shinyun,” he yelled as he got closer, to be heard over the wind and the rumbling backdrop of thunder. But also because he was mad. “You give me a beautiful gift and then you attack us? I thought our conversation went well!”

Shinyun gazed at him impassively. “You could summon just as large an army, you know.”

“I couldn’t,” said Magnus, “but also I wouldn’t. For one thing, it’s extremely illegal.” Shinyun barked a laugh. “For another, then we would have twice as many demons, rather than no demons, which is my preference.”

“Oh, but you could,” Shinyun said. There was a rush of wind and Magnus became aware of two Ala demons rushing at him, one from each side. Shinyun, he thought grimly, was trying to make a point.

Well, fine. How about this point?

With a roar, Magnus thrust out his arms, letting the simmering bubble of magic deep in his chest come to a full boil. Bolts of lightning crackled out from both of his hands, bright blue and knife-edged. The Ala demons were split clean in half by the two bolts and fell away. Magnus lowered his hands—to his surprise, he had had no trouble keeping himself aloft during his attack.

While Shinyun’s face was as unexpressive as ever, Magnus got the distinct impression that she was smirking at him. “You see? Whatever you may think of my master, the Svefnthorn’s power is undeniable.”

“What does your master think of me?”

She laughed. “He doesn’t know anything about you yet. But I think he’s going to be very pleased when he does.”

“Why would he be pleased?” Magnus said incredulously. “Because you’re strengthening one of his enemies?”

She laughed. “You don’t know Sammael at all.”

“I agree,” said Magnus. “I do not.” He looked around. “Looks like my friends are almost finished mopping up your demon army.”

Shinyun shrugged. “There are more where they came from. But I’ll go. I just wanted you and your friends to see a little demonstration of what the thorn makes possible.”

She raised her hands, and as one, the demons far below them froze. As one, they turned to look at Shinyun. Magnus saw one of them crumple and vanish as a Shadowhunter, he couldn’t tell who, took the opportunity to thrust a blade through its back.

Another gesture, and all the remaining demons rose into the air. They rose until they began to be drawn back into the black cloud whose shadow they had been fighting in.

“Wait,” said Magnus. “Where’s Ragnor? I want to—I need to speak to him.”

“I’ll pass on the message,” Shinyun drawled, “but he’s very busy.”

Magnus yelled, “How did he evade our Tracking magic? What are you trying to accomplish? Where’s the Book?”

Shinyun just laughed. She rose into the storm cloud above her, still laughing. Magnus had to grant her a certain classic villainous style.