“I don’t know how I did it exactly. I just remember I saw…” She searched for a way to describe it. “You know how normally in a tithe you see your own veins? I saw mine, but I saw yours, too, beside me, and Akeylah beside you… even Audrina, I think, this big black cloud.” Zofi shook herself. “I threw a shield around you, the same way I would’ve done to myself. I didn’t even know if it would work, but it seemed like the only way to help.”

“Did it…” Ren cleared her throat. “Did it leave a mark?”

Zofi blinked. She hadn’t even thought to check. She tugged her breeches down far enough to squint at her thigh, where she’d cracked the boost. Sure enough, a pale blue glow shone in a jagged X where the glass had broken her skin. “Yes.” Zofi’s voice shook.

She’d worked the Vulgar Arts. Just like her mother the curseworker.

It stunned her, how easy it had been. Instinctive. So similar to a normal tithe, to one she’d work on herself. It raised all over again the questions she’d had while reading her mother’s journal. Should there be some exceptions? Should Vulgar Arts that worked in someone else’s favor, to help or save them, really be called curses?

“Thank you,” Ren whispered. Zofi could see Ren’s hands wrapped around the bars of the neighboring cell, if she tilted forward far enough.

Zofi slid over to join her. “You’d have done the same for me.”

That’s what got her thinking.

Shield tithes guarded the tither from being attacked, but also made it impossible for them to use any other tithes or curses for a whole day. It was like a dam, blocking a person from the Arts.

If Zofi could shield another person as easily as she could shield herself, she could also use the shield for more than just protection…

“Ren.” Her voice went sharp, urgent. “If all three of us shielded Audrina at once, I think we might be able to bind her, stop her from being able to curse anyone. At least for a day.”

Ren fell silent, thinking. “Maybe,” she replied at last. “But what good would it do?”

“Akeylah said the heir was threatening Rozalind. It’s why Akeylah agreed to hold the Blood Ceremony in the first place. I’d bet anything Audrina is threatening us, too, now. But if we could bind Audrina, she’d have no bargaining power.”

“Aud was strong enough to break through my shield tithe.” Ren tapped a fingernail on the metal bar. “And you said yourself the way her parents conceived her, the tithe they did, makes her stronger than anyone when it comes to the Arts.”

“Stronger than you and me and Akeylah combined?” Zofi watched the condensation along the ceiling. Three droplets intersected, joined together in a wide trickle down the wall.