“Having someone who’s sworn to shield you from danger,” said Livvy, her eyes shining. “Someone who would put their hands in a fire for you.”

Briefly Emma remembered that Jem had once told her that his parabatai, Will, had thrust his hands into a fire to retrieve a packet of medicine that would save Jem’s life. Maybe she shouldn’t have repeated the story to Livvy.

“In the movies Watson throws himself in front of Sherlock when there’s gunfire,” Ty said, looking thoughtful. “That’s like parabatai.”

Livvy looked mildly outfoxed, and Emma felt for her. If Livvy said it wasn’t like parabatai, Ty would argue. If she agreed it was, he would point out you didn’t need to be parabatai to jump in front of someone when there was danger. He wasn’t wrong, but she sympathized with Livvy’s desire to be parabatai with Ty. To make sure her brother was always by her side.

“Got it!” Drusilla announced suddenly. She stood up from rummaging around in the map chest with a long piece of parchment in her hands. Livvy, abandoning the parabatai discussion, hurried over to help her carry it to the table.

In a clear bowl on the table’s center was a heap of sea glass the Blackthorns had collected over the years—lumps of milky blue, green, copper, and red. Emma and Ty used the blue glass to weigh down the edges of the ley line map.

Tavvy, now sitting on the edge of the table, had begun sorting the rest of the sea glass into piles by color. Emma let him; she didn’t know how else to keep him distracted just now.

“Ley lines,” Emma said, running her index finger over the long black lines on the map. It was a map of Los Angeles that probably dated back to the forties. Landmarks were visible under the ley lines: the Crossroads of the World in Hollywood, the Bullocks building on Wilshire, the Angels Flight railroad in Bunker Hill, the Santa Monica Pier, the never-changing curve of the coast and the ocean. “All the bodies were left under the span of a ley line. But what Magnus said is that there are places where all the ley lines converge.”

“What does that have to do with anything?” Livvy asked, practical as always.

“I don’t know, but I don’t think he would have said it if it didn’t matter. I imagine the place of convergence has some pretty powerful magic.”

As Ty applied himself to the map with renewed vigor, Cristina came into the library and gestured for Emma to come talk to her. Emma slid off the table and followed Cristina to the coffeemaker by the window. It was witchlight powered, which meant there was always coffee, although the coffee wasn’t always very good.

“Is Julian all right?” Emma asked. “And Mark?”

“They were talking when I left.” Cristina filled two cups with black coffee and dumped in sugar from a small enamel pot on the windowsill. “Julian calmed him down.”

“Julian could calm anyone down.” Emma picked up the second cup of coffee, enjoying the warmth against her skin, though she didn’t really like coffee and didn’t tend to drink it. Besides, her stomach was tied in so many knots she didn’t think she could force anything down.

She walked back toward the table where the Blackthorns were arguing about the ley line map. “Well, I can’t help it if it doesn’t make sense,” Ty was saying peevishly. “That’s where it says the convergence is.”

“Where?” Emma asked, coming up behind him.

“Here.” Dru pointed at a circle Ty had sketched on the map in pencil. It was over the ocean, farther out from Los Angeles than Catalina Island. “So much for anyone doing magic there.”

“Guess Magnus was just making conversation,” said Livvy.

“He probably didn’t know—” Emma began, and broke off as the library door opened.

It was Julian. He stepped into the room and then moved to the side, diffidently, like a conjuror presenting the result of a trick.

Mark moved into the doorway after him. Julian must have gotten Mark’s old things out of the storeroom. He was wearing jeans that were slightly short on him—probably a pair of his old ones—and one of Julian’s T-shirts, heather gray and washed to a soft fadedness. In contrast, his hair looked very blond, almost silvery. It hit his shoulders, looking slightly less tangled, as if he’d brushed the twigs out of it at least.

“Hello,” he said.

His siblings looked at him in silent, wide-eyed astonishment.

“Mark wanted to see you,” Julian said. He reached around to ruffle the hair on the back of his neck, looking bemused, as if he had no idea what to do next.

“Thank you,” Mark said. “For the gifts of welcome you gave me.”

The Blackthorns continued to stare. Nobody moved except Tavvy, who slowly laid his sea glass down on the table.

“The box,” Mark clarified. “In my room.”

Emma felt the coffee cup she was holding plucked out of her hand. She made an indignant noise, but Cristina was already holding it, crossing the room, past the table, and walking up to Mark, her back straight. She held out the mug.

“Do you want some?” she said.

Looking relieved, he took it. He lifted it to his mouth and swallowed, his whole family watching him in amazed fascination as if he were doing something no one had ever done before.

He grimaced. Moving away from Cristina, he coughed and spit. “What is that?”