Emma swung herself off the cycle. Mark followed, and they stood for a moment, the sea a gleam in the distance, the hill rising dark in front of them.

“You drive too fast,” said Mark.

Emma snorted and checked the strap of Cortana where it fastened across her chest. “You sound like Julian.”

“It brought me joy,” Mark said, moving to stand beside her. “It was as if I flew with the Hunt again, and tasted the blood of the sky.”

“Okay, you sound like Julian on drugs,” Emma muttered. She glanced around. “Where are we? Is this the ley line convergence?”

“There.” Mark pointed at a dark opening in the rock of the hill. As they moved toward it, Emma reached back to touch the hilt of Cortana. Something about the place was giving her shivers—maybe it was simply the power of the convergence, but as they neared the cave, and the hair rose on the back of her neck, she doubted it.

“The grass is flat,” she said, indicating the area around the cave with a sweep of her hand. “Trampled. Someone’s been walking here. A lot of someones. But there are no fresh tire tracks on the road.”

Mark glanced around, head tilted back, like a wolf scenting the air. His feet were still bare, but he seemed to have no problem walking on the rough ground, despite the thistles and sharp rocks visible between the grasses.

There was a sharp, bright trill—Emma’s phone ringing. Jules, she thought, and snatched it out of her pocket.

“Emma?” It was Cristina, her low, sweet voice oddly startling—a sharp reminder of reality after the unreal flight through the sky. “Where are you? Did you find Mark?”

“I found him,” Emma said, glancing over toward Mark. He appeared to be examining the plants growing around the mouth of the cave. “We’re at the convergence.”

“What? Where is it? Is it dangerous?”

“Not yet,” Emma said as Mark ducked into the cave. “Mark!” she called. “Mark, don’t—Mark!”

The phone connection dropped. Swearing, Emma stuck the phone back into her pocket and took out her witchlight. It came on, soft and bright, raying out through her fingers. It illuminated the mouth of the cave. She headed toward it, cursing Mark under her breath.

He was just inside the cave, looking down at more of the same plants, clustering around the dry, soft stone. “Atropa belladonna,” he said. “It means ‘beautiful lady.’ It’s poisonous.”

Emma made a face. “Does it grow around here normally?”

“Not in this quantity.” He reached down to touch it. Emma caught his wrist.

“Don’t,” she said. “You said it was poisonous.”

“Only if swallowed,” he said. “Hasn’t Uncle Arthur taught you anything about the death of Augustus?”

“Nothing I haven’t worked hard to forget.”

Mark straightened up, and she let go of him. She flexed her fingers. There was wiry strength in his arms.

As he moved forward into the cave, which began to narrow into a tunnel, she couldn’t help but remember Mark the last time she had seen him, before he had been taken by Sebastian Morgenstern. Smiling, blue-eyed, short pale hair curling over the tips of his pointed ears. Broad-shouldered—or at least she, at twelve, had thought so. Certainly he had been bigger than Julian, taller and broader than all of them. Grown up.

Now, prowling ahead of her, he seemed a feral child, hair gleaming in the witchlight. He moved like a cloud across the sky, vapor at the mercy of wind that could tear it to shreds.

He vanished around a bend of rock, and Emma almost closed her eyes against the image of a vanished Mark. He belonged to the past that contained her parents, and you could drown in the past if you let it have you while you were working.

And she was a Shadowhunter. She was always working.

“Emma!” Mark called, his voice echoing off the walls. “Come and see this.”

She hurried after him down the tunnel. It opened out into a circular chamber lined with metal. Emma turned on her heel in a slow circle, staring. She wasn’t sure what she had expected, but not something that looked like the inside of an occult ocean liner. The walls were bronze, covered in strange symbols, a scrawled mixture of languages: some demonic, some ancient but human—she recognized demotic Greek and Latin, a few passages from the Bible. . . .

Two massive glass doors like portholes were set into the walls, shut and bolted with rivets. A strange metal ornament had been fixed in the wall between them. Through the glass, Emma could see only surging darkness, as if they were underwater.

There was no furniture in the room, but a circle of symbols, done in chalk, was drawn onto the smooth black stone floor. Emma brought out her phone and began to take pictures. The flash going off seemed eerie in the dimness.

Mark moved toward the circle. “Don’t—” Emma lowered her phone. “Go in there,” she sighed.

He was already inside the circle, looking around curiously. Emma couldn’t see anything in there with him besides bare floor.

“Please come out,” she said wheedlingly. “If there’s some magic spell in there and it kills you, explaining to Jules is going to be so awkward.”

There was a faint shimmer of light as Mark stepped out of the circle. “‘Awkward’ seems like an understatement,” he said.

“That’s the point,” Emma said. “That’s why it’s funny.” He looked blank. “Never mind.”

“I read once that explaining a joke is like dissecting a frog,” Mark said. “You find out how it works, but the frog dies in the process.”

“Maybe we should get out of here before we die in the process. I took some pictures with my phone, so—”

“I found this,” Mark said, and showed her a square leather object. “It was inside the circle along with some clothes and what looked like”—he frowned—“broken teeth.”

Emma snatched the object out of his hand. It was a wallet—a man’s wallet, semi-scorched by fire. “I didn’t see anything,” she said. “The circle looked empty.”

“Glamour spell. I felt it when I passed through.”

She flipped the wallet open, and her heart leaped. Pressed behind plastic was a driver’s license with a familiar picture. The man whose body she’d found in the alley.

There was money in the wallet and credit cards, but her eyes were fixed on the license and his name—Stanley Albert Wells. The same longish, graying hair and round face she remembered, only this time his features weren’t twisted up and stained with blood. The address under the name had been burned to illegibility, but the birth date and other information were clear.

“Mark. Mark!” She waved the wallet over her head. “This is a clue. An actual clue. I think I love you.”

Mark’s eyebrows went up. “In Faerie, if you said that, we would have to pledge our troth, and you might put a geas upon me that I would not stray from you or I would die.”

Emma shoved the wallet in her pocket. “Well, here it’s just an expression that means ‘I like you very much’ or even ‘Thanks for the bloodstained wallet.’”

“How specific you humans are.”

“You’re human, Mark Blackthorn.”