Ariadne and Anna stood back-to-back, fighting like parabatai might, their movements in sync. Though they were certainly not parabatai. It would be very wrong to feel about a parabatai the way Anna felt about Ariadne. There was no mistaking it, Anna thought, though it was an awkward revelation to have in the middle of a demon fight.

She was definitely in love with Ariadne Bridgestock.

Jem entered the house through the open door, his staff at the ready. The room was quiet. There was a tremendous amount of blood on the floor, and the torn remains of a human.

“Herein!” said a voice. “I was hoping you would come.”

Jem turned. Leopolda Stain was sitting on a large brocade chair, holding the head of a woman in her lap. Jem raised his staff.

You have murdered innocent mundanes, Jem said.

“They slew themselves,” Leopolda said. “They were playing with fire. They were burned. You know of such creatures. They believe they understand magic. They must come to understand its true nature. I do them a service. They will not call another demon. If I wanted to teach them a lesson, where’s the harm? There is hellfire in me, but I do not think I am your chief concern.”

Jem was torn. His instinct was to strike her down for what she had done, and yet …

“You hesitate, James Carstairs,” she said with a smile.

My name is Brother Zachariah.

“You were James Carstairs, the Shadowhunter who was addicted to yin fen. You were acquainted with Axel Mortmain, the one they called the Magister, I think?”

At the sound of Mortmain’s name, Jem lowered his staff.

“Ah,” Leopolda said with a smile. “You remember dear Axel.”

You knew him?

“Quite well,” she said. “I know many things. I know a warlock helps run the Institute here, yes? Named Tessa Herondale. She is a Shadowhunter, and she can bear no Marks. She is married to your parabatai.”

Why are you asking me about Tessa? Jem said. It was as if cold fingers were touching his spine. He did not like this warlock. He did not like her interest in Tessa and Will.

“Because you have been in the Shadow Market, asking many questions about her. About her father. Her demonic father.”

She let the head roll from her lap.

“As I said, I knew Mortmain,” she said. “Since you have been asking about him and how Tessa was created, news has trickled back to me—one of his only remaining friends. I believe you are curious about how Mortmain created Tessa. You seek the demon he summoned to be her father. If you put your weapon away, perhaps we can have a conversation.”

Jem did not set down his staff.

“She might not have been too curious about her demon father before”—Leopolda played with the gold netting in her hair—“but now that she has children … and those children show signs of their demon heritage … I imagine things are very different?”