At the time, Liam’s German was perfunctory at best, so he could only skim the surface. Something about a book, Porta ad Tenebras, that had been confiscated by the German army but that Kreutzer was trying to track down. The key to wrenching open the gates. It details Sicarelli’s meeting with the beings on the other side, my research tells me. How he built the first bridge. It might prove valuable later, Kreutzer said—but first their basic theories had to be confirmed. My experiments continue apace, but we need more. Has your colleague found the frequency yet?

Liam kept leafing through the notebook, a new urgency thrumming in his veins. The pages were wrinkled from being gripped with sweaty hands; Pitr’s cursive was nearly indecipherable. Even the few passages in English were a challenge, and the deeper he went, the more the writing unraveled, panicked and swift. Strange creatures appeared in the margins, skeletal dogs with too many joints in their limbs and people with seams in their skin.

But then one page, the last, carried a single equation in English, splotched with ink and heavily underlined:

Two requirements for opening:

RESONANCE

BLOOD

Liam looked up, an unnamed fear gripping him. Just what had Pitr done?

And then he froze: There was a dark figure behind him in the mirror. Standing. Looming. Heavy bruises of exhaustion beneath his eyes. In the mirror, their gazes locked.

“Come back to bed,” Pitr said. His voice was so low Liam felt it more than heard it; it traced a finger down his arm and held his heart in its grasp. Liam sensed something feral and unrestrained beneath the tone.

Resonance. Blood. The resonance part, Liam understood—it fit his own theories neatly enough. The right wavelength could create a gap in space itself, teasing open their universe like dough stretching until it tore in the middle. But blood—

Pitr reached for Liam’s wrist. “Now.”

Liam’s foolish, petulant heart, the one that drove him to fight back against grade school bullies, that urged him to throw himself between his parents when his father was on a rampage—his foolish heart wanted to protest. He’d do anything to prove to Pitr he was old enough, clever enough, brave enough. That he was deserving. That he was worthy—of Pitr and whatever Pitr sought.

But the Liam who’d watched his father win anyway, who’d glimpsed the suffering men like him wrought, who had to handle the aftermath of a world he couldn’t control and a heart he couldn’t keep from breaking—that Liam deserved more.

“Don’t be reckless,” Liam said. “We don’t know what we’re dealing with. I can’t lose you—”