“Okay.” Emma looked up at the gulls wheeling overhead. “Let’s go sit down. I don’t want to get washed away when the tide comes in.”

They settled in farther up the beach, where the sand was warm from the sunlight. Emma kicked her shoes off to dig her toes in, exulting in the grainy feeling. Julian laughed.

She looked at him sideways. “What is it?”

“You and the beach,” he said. “You love the sand, but you hate the water.”

“I know,” she said, widening her eyes at him. “Isn’t it ironic?”

“It’s not ironic. Irony is the unexpected outcome of an expected situation. This is just one of your quirks.”

“You shock me,” Emma said, pulling out her phone. “I am shocked.”

“Sarcasm noted,” he said, turning the phone over in his right hand. Cristina’s photos from the previous night had loaded. As he ran his eyes over them, she explained how she’d followed the tip from Johnny Rook to the Sepulchre, the way she’d found the body, and Diana’s scolding following Rook’s visit to the Institute. As she spoke, she relaxed, her odd new awareness of Julian fading. This was normal, this was them the way they always were: talking, listening, working as parabatai. “I know these are the same markings,” she finished. “I’m not out of my mind, am I?”

Julian looked up at her. “No,” he said. “But Diana thinks that if you look into this, it’ll compromise the Clave’s willingness to let Helen come home?”

“Yeah.” Emma hesitated, then reached out and took his hand. The sea-glass bracelet on his left wrist clinked musically. She felt his calluses against her fingers, as familiar to her as a map of her own bedroom. “I would never do anything to hurt Helen, or Mark, or you,” she said. “If you think Diana’s right, I won’t—” She swallowed. “I’ll leave it alone.”

Julian glanced down at their entwined fingers. He was still, but a pulse had started up at the base of his throat; she could see it beating, hard. It must have been the mention of his sister.

“It’s been five years,” he said, and drew his hand back. He didn’t yank it out of her grip or anything like that, just drew it back as he turned toward the water. A completely natural movement that nevertheless left her feeling awkward. “The Clave hasn’t budged on letting Helen come home. They haven’t budged on looking for Mark. And they haven’t budged on considering that maybe your parents weren’t killed by Sebastian either. It seems wrong to sacrifice finding out what happened to your family for a doomed hope.”

“Don’t say it’s doomed, Jules—”

“There’s another way of thinking about this too,” he said, and she could practically see the gears turning in his quick brain. “If you actually solved this, if we solved this, the Clave would owe us. I believe you that whoever killed your parents, it wasn’t Sebastian Morgenstern. We’re looking at a demon or some other force that has the power to murder Shadowhunters and get away with it. If we defeated something like that . . .”

Emma’s head was starting to ache. Her ponytail holder was twisted hard into her hair; she reached up to loosen it. “Then they’d give us special treatment, you mean? Because everyone would be watching?”

“They’d have to,” Julian said. “If everyone knew what we did. And we could make sure everyone knew.” He hesitated. “We do have connections.”

“You don’t mean Jem, do you?” asked Emma. “Because I don’t know how to reach him.”

“Not Jem and Tessa.”

“So Jace and Clary,” Emma said. Jace Herondale and Clary Fairchild ran the New York Institute. They were some of the youngest Shadowhunters ever to hold such a senior position. Emma had been friends with Clary since she was twelve, when Clary had first followed her out of the Council Hall in Idris, the only person among all the Clave, it seemed, to care that she had lost her parents.

Jace was probably one of the best Shadowhunters who had ever lived, purely in terms of fighting prowess. Clary had been born with a different talent: She could create runes. It was something no other Shadowhunter had ever been able to do. She had explained once to Emma that she couldn’t force the runes that came to her—either they did or they didn’t. Over the years she’d added several useful runes to the Gray Book—one for breathing underwater, another for running long distances, and a rather controversial one for birth control that had nevertheless quickly become the most often used rune in the lexicon.

Everyone knew Jace and Clary. That was how it went when you saved the world. They were heroes to most—to Emma they were people who had held her hands during the darkest part of her life.

“Yeah.” Julian reached around, rubbed the back of his neck. He looked tired. There was a faint sheen to the skin under his eyes, as if it was stretched thin with exhaustion. He worried at his lip with his teeth, as he always did when he was anxious or bothered. “I mean, they were made some of the youngest heads of an Institute ever. And look at what the Clave did for Simon, and for Magnus and Alec. When you’re a hero, they’ll do a lot for you.” Julian stood up, and Emma rose with him, pulling the band out of her ponytail. Her hair came free, tumbling in waves down her shoulders and her back. Julian looked at her quickly, and then away.

“Jules—” she began.

But he had already turned away, heading back toward the road.

She shoved her feet into her shoes and caught up with him where the sand rose up toward the pavement. “Is everything okay?”

“Of course. Here, sorry, I forgot to give you this back.” He handed Emma her phone. “Look, the Clave makes their rules. And they live by their rules. But that doesn’t mean that with the right pressure, the rules never change.”

“You’re being cryptic.”

He smiled, the corners of his eyes crinkling.

“They don’t like letting Shadowhunters as young as we are get involved with serious issues. Never have. But Jace and Clary and Alec and Isabelle saved the world when they were our age. They were honored for it. Results—that’s what makes them change their minds.”

They had reached the highway. Emma looked up, toward the hills. The Institute was perched on a low bluff over the coast road.

“Julian Blackthorn,” she said as they crossed the highway. “You revolutionary, you.”

“So we’ll look into this, but do it quietly,” Julian said. “First move, compare the photos of the body you found to the photos of the bodies of your parents. Everyone will want to help. Don’t worry.”

They were halfway up the Institute road. Cars were backed up even now, mundanes commuting to work downtown. Sunlight sparked off their windshields.

“And if it turns out the markings are just gibberish, and it’s some random lunatic on a murder spree?”

“Couldn’t be a spree. Sprees happen all at once, but in different locations. Like if you drive from place to place shooting people, that’s a spree.”

“So what’s this? A mass murder?”

“Mass murders also all take place at the same time, but are in the same location,” Julian said loftily, in the same tone he used when explaining to Tavvy why he couldn’t have Cheerios for breakfast. “This is definitely a serial killer. That’s when the murders are spaced out over time.”