Emma said, “‘First thirteen and then the last.’ He’s killed thirteen. He’s got one last one to go and then he’s done. He’ll have enough magic to bring back Lady Midnight.”

“So there’ll be one more,” said Julian. “One that might be different from the last.”

“There must be more instructions than this,” said Ty. “No one could figure out exactly how to complete this spell just from this rhyme.” He looked around, a flicker of uncertainty in his gray eyes. The look he got very rarely, but sometimes, when he thought that there was something in the world that everyone understood but him. “Could they?”

“No,” Mark said. “But the rhyme tells you where to look for the rest of the instructions. ‘Search not the book of angels gray’—the answer is not in the Gray Book. Nor is it in the Book of the White or in the Red Texts.”

“It is in the Black Volume of the Dead,” said Diego. “I have heard of that book, in the Scholomance.”

“What is it?” said Emma. “Are there copies? Is it something we could get hold of?”

Diego shook his head. “It is a book of very dark magic. Almost legendary. Even warlocks are forbidden to own it. If there are copies, I do not know where. But we should set ourselves to find out, tomorrow.”

“Yeah,” Livvy said, her voice blurry with sleep. “Tomorrow.”

“Do you need to go to bed, Livvy?” Julian asked. It was a rhetorical question: Livvy was drooping like a wilted dandelion. At his words, though, she forced herself bolt upright.

“No, I’m fine, I could stay up—”

Ty’s face changed subtly as he looked at his twin sister. “I’m exhausted,” he said. “I think we should all go to sleep. In the morning we’ll be able to concentrate better.”

Julian doubted Ty was actually tired at all: When he was engaged in a puzzle, he could stay up for days at a time. But Livvy nodded gratefully at the words.

“You’re right,” she said. She slid off the chair she was sitting on and picked up Tavvy, handing him back his book. “Come on,” she said. “You should definitely be in bed.”

“I helped, though, didn’t I?” Tavvy asked as his sister carried him toward the door. He was looking over at Julian as he said it, and Julian remembered himself as a child, looking toward Andrew Blackthorn that way. A boy looking to his father, seeking approval. “You didn’t just help,” said Julian. “I think you may have solved it, Tavs.”

“Yay,” said Tavvy sleepily, and put his head down on Livvy’s shoulder.

The others soon followed Ty and Livvy to bed, but Emma found she couldn’t sleep. She found herself, instead, sitting on the front steps of the Institute before the sun rose.

She was in flip-flops, a tank top, and pajama bottoms. The air coming off the ocean was chilly, but she didn’t feel it. She was staring at the water.

From every angle of the steps you could see the ocean: blue-black in the rising morning now, like ink, raked with swells of white foam where the waves broke far out to sea. The moon had shrunk and cast an angular shadow across the water. A blue-and-silver dawn.

She remembered the spilling cold of that blue ocean all around her. The taste of salt water and demon blood. The feeling that the water was pressing her down, crushing her bones.

And the worst part, the fear that once her parents had felt the same pain, the same panic.

She thought of Julian then. The way he had looked in the dining room. The strain in his voice as he’d stood there telling her and Mark everything he’d done for the past five years.

“Emma?”

Emma half-turned and saw Perfect Diego coming down the steps. He looked immaculate, despite the night they’d had, even his boots polished. His dark brown hair was thick and fell charmingly over one of his eyes. He looked a bit like a prince in a fairy-tale book.

She thought of Julian again. His untidy hair, his bitten nails, his dusty boots, the paint on his hands.

“Hey, Perfect Diego,” she said.

“I wish you wouldn’t call me that.”

“You wish in vain,” Emma said. “Where are you going? Is Cristina all right?”

“She’s asleep.” Perfect Diego looked out at the ocean. “It’s very beautiful here. You must find it peaceful.”

“And you must be kidding.”

He flashed a fairly perfect smile. “You know, when there aren’t murders happening and small armies surrounding the place.”

“Where are you going?” Emma asked again. “It’s practically dawn.”

“I know the cave will not be open, but I am going to the convergence site to see it for myself. The demons should have disbanded by now. I want to take another look around the area, see if there is anything you missed.”

“You are just bursting with tact, aren’t you?” Emma said. “Fine. Go ahead. See what we all missed while we were nearly being cut to pieces by giant grasshopper demons.”

“Mantids aren’t technically grasshoppers—”

Emma glared. Diego shrugged and jogged to the foot of the steps. He paused there and looked back over his shoulder at her.

“Does anyone else in the Clave know about your investigation?” he said. “Anyone but your family?”

“Just Diana,” said Emma.

“Diana is your tutor?” When Emma nodded, he frowned. “Weren’t Jace Herondale and the Lightwoods betrayed by their own tutor?”

“She’d never betray us,” Emma said, outraged. “Not to the Clave or to anyone else. Hodge Starkweather was different.”

“Different how?”

“Starkweather wasn’t Diana. He was a minion of Valentine’s. Diana is a good person.”

“So where is she now?” Diego asked. “I’d like to meet her.”

Emma hesitated. “She . . .”

“She’s in Thailand,” said a voice from behind them. It was Julian. He’d shrugged on a hooded army jacket over his jeans and T-shirt. “There was a witch there she wanted to question about energy spells. Someone she knew when she was younger.” He paused. “We can trust her.”

Diego inclined his head. “I didn’t mean to imply otherwise.”

Julian leaned against one of the pillars, and he and Emma watched as Diego strode away across the trampled grass and headed down the road. The moon had disappeared entirely and the eastern sky was beginning to turn pink.

“What are you doing out here?” Julian said finally in a quiet voice.

“I couldn’t sleep,” said Emma.

Julian had his head tipped back, as if he were bathing in the dim illumination of the dawn. The strange light made him into something else, someone made out of marble and silver, someone whose inky curls clung to his temples and neck like the acanthus leaves in Greek art.

He wasn’t perfect, like Diego, but to Emma, there had never been anyone more beautiful.

“We’re going to have to talk about this eventually,” she said. “What you told me and Mark.”

“I know.” He looked down at his long legs, the frayed hems of his jeans, his boots. “I had hoped—I suppose I’d hoped it would never happen, or that at least we’d be adults when it did.”