“We do if the blood being shed is faerie blood,” said Kieran. He looked around at their surprised faces. “As you know, the killer has been murdering and mutilating faeries, too. That is why Iarlath was at the Sepulchre. That is why Emma Carstairs encountered him. You were hunting the same prey.”

Iarlath reached into his cloak and drew out a handful of glittering mica. He tossed it into the air, where the particles hung and separated, coalescing into three-dimensional images. Images of bodies, faerie bodies—human-looking gentry faeries, all dead. All had skin carved with the spiky dark markings that had adorned the body Emma had found in the alley.

Emma found herself unconsciously leaning forward, trying to get a better view of the illusion. “What are these? Magic photographs?”

“Memories, preserved with magic,” said Iarlath.

“Illusions,” said Julian. “Illusions can lie.”

Iarlath turned his hand to the side, and the images changed. Emma was suddenly looking at the dead man she’d found in the alley three nights ago. It was an exact image, down to the twisted look of horror on his face. “Does this lie?”

Emma stared at Iarlath. “So you saw him. You must have come across him before I did. I wondered.”

Iarlath closed his hand, and the glittering pieces of mica fell to the floor like drops of rain, the illusion vanishing. “I did. He was already dead. I could not have helped him. I left him for you to find.”

Emma said nothing. It was quite evident from the picture that Iarlath was telling the truth.

And faeries didn’t lie.

“Shadowhunters have been killed too, we know,” Kieran said.

“Shadowhunters are often killed,” said Uncle Arthur. “There is no safe place.”

“Not so,” said Kieran. “There is protection where there are protectors.”

“My parents,” Emma said, ignoring Julian, who was shaking his head at her, as if to say, Don’t tell them, don’t share, don’t give them anything. She knew he was likely right—it was in the nature of faeries to take your secrets and turn them against you. But if there was the chance, the smallest chance that they knew something . . . “Their bodies were found with those same markings on them, five years ago. When the Shadowhunters tried to move them, they crumbled to ashes. The only reason we know about the markings was because the Nephilim took photos first.”

Kieran glanced at her with shimmering eyes. Neither looked quite human: The black eye was too dark, the silver too metallic. And yet the overall effect was haunting, inhumanly beautiful. “We know about your parents,” he said. “We know of their deaths. We know of the demon language with which their bodies were inscribed.”

“Mutilated,” Emma said, her breath catching, and felt Julian’s eyes on her, a reminder that he was there, a silent support. “Disfigured. Not inscribed.”

Kieran’s expression didn’t change. “We understand as well that you have tried for years to translate or understand the markings, with no success. We can help you change that.”

“What are you saying, exactly?” Julian demanded. His eyes were guarded; his whole posture was. The tension in his body kept Emma from bursting out with questions.

“The scholars of the Unseelie Court have studied the markings,” said Iarlath. “It looks like a language from an ancient time of Faerie. One long before your human memory. Before there were Nephilim.”

“Back when faeries were more closely tied to their demonic ancestry,” said Arthur hoarsely.

Kieran’s lip curled as if Arthur had said something distasteful. “Our scholars began to translate it,” he said. He drew several sheets of thin, parchment-like paper from his cloak. Emma recognized on them the markings she was so familiar with. Below the markings were more words, written in a spidery script.

Emma’s heart started to pound.

“They translated the first line,” he said. “It does appear to perhaps be part of a spell. There our knowledge fails us—the Fair Folk do not deal in spells; that is warlock territory—”

“You translated the first line?” Emma burst out. “What is it?”

“We will tell you,” said Iarlath, “and give you the work our scholars have done so far, if you will agree to our terms.”

Julian looked at them with suspicion. “Why would you translate only the first line? Why not the whole thing?”

“Scarce had the scholars worked out the meaning of that first line when the Unseelie King forbade them to continue,” said Kieran. “The magic of this spell is dark, demonic in origin. He did not want it awakened in Faerie.”

“You could have continued the work yourself,” said Emma.

“All faeries are forbidden by the King to touch these words,” snapped Iarlath. “But that does not mean our involvement ends. We believe this text, these markings, may help lead you to the killer, once they are understood.”

“And you want us to translate the rest of the markings?” Julian said. “Using the line you’ve worked out as a key?”

“More than that,” said Iarlath. “The translation is but the first step. It will lead you to the murderer. Once you have found that person, you will turn them over to the Unseelie King that they might stand trial for the murder of the fey and receive justice.”