“This could do it?” I held up the key, reclaiming his attention. “A god made it.”

Taproot cocked his head, staring at Loki’s key. He frowned and reached into a pocket for a lens held in a silver hoop. Holding it to his eye, he leaned forward for a close inspection. “The one who made this gave me my first job.” He straightened with a smile. “A remarkable piece of work.” He looked around at us again. “It’s clever. Very clever . . . It’s possible. Not likely. But possible. How are you going to get it there?”

“We walk,” Snorri said.

“Ride,” I said. I’d done enough walking to last a lifetime.

Dr. Taproot’s face fell. The change would have been comical if it didn’t bode so poorly for me. “You’ve no help? No plan?”

“The plan appears to be walking to the Wheel and turning off the engines that drive it,” I said, my voice sour. “Do you think it would be more of a one-man job, Taproot?”

“One, one thousand, it makes little difference.” His hands returned to the wrestling they’d been caught in during his stasis. “Your dreams are what will tear you apart. Every man is the victim of his own imagination: we all carry the seeds of our own destruction.” He tapped a long finger to his forehead. “It feeds on your fears.”

“So we need another plan . . . We need to—”

“There is no other plan.” Snorri cut me off. “Taproot has watched a thousand years go by. His people built Osheim, made this happen. The ancient machines speak their secrets to him. And he hasn’t stopped the slow roll of this world into oblivion.”

“It’s true.” Taproot hugged himself. “Go to Osheim. Perhaps the key . . .” A tremor ran through the chamber. “We should go.”

I was already at the door, Loki’s key pressed to the button pad. “Open!”

The heavy valve slid back without a whisper.

“Well that’s encouraging.” Taproot at my side. “That is no simple lock.”

We stepped aside to let Kara and Hennan through. I would claim chivalry but the truth is she held the light. I took a last glance at the room as shadows reclaimed it. The rotting horror of the dead Builder’s head watched us go.

“I could have sworn . . .” That it had been looking the other way when it first fell. I followed hard on Snorri’s heels, cursing him to hurry. Once through I held the key to the button pad on the outside and commanded the door to close.

Kara and Hennan were already climbing, an island of light above us. “Go on.” I slapped Snorri’s shoulder. “If the kid falls you can catch him.”

I took the opportunity to plead my case alone with Taproot in the gloom at the bottom of the handholds. “Look, I can’t go to Osheim. You said it feeds on fears. Christ, I’m all fear. Fear and bones. That’s all I’ve got. I’m the worst person to send—the absolute worst. You should go with Snorri. Look, I’ll just give you the key and—”

“I have other things to do. The data-echoes in the deepnet—”

“What?”

He drew in a sigh. “There are Builder ghosts in machines beneath the earth. They too will be destroyed if the Wheel turns too far. They can’t stop the Wheel’s engines safely but the engines only turn the Wheel because we use the power it gives us. They can’t stop the engines but they can stop what’s driving those engines on.”

That sounded depressingly familiar. Grandmother had said something similar. “Us?”

“Yes. There is a faction—a faction growing in strength—that wants to use the remaining nuclear arsenal to wipe out humanity. Without people to exercise the . . . to use magic, the Wheel should stop turning.”

“What can you do?” The Kendeth ghost that Garyus had summoned from the box had spoken of this. I had hoped he was lying.

“I can talk to them. Gather evidence. Politic. Delay. And that delay is only useful if someone else acts in it.”

I reached up and found a handhold in the dark. “All I’m saying is that pretty much anyone would be a better choice for this than me.” I started to climb.

“Fear is a necessary metric without which the modelling of risk and consequence would serve no purpose.”

“What?” He’d gone back to talking nonsense.

“No man is without fears, Prince Jalan. The key is designed to unlock things. If it has gathered you four together then perhaps you’re the best chance we have to unlock Osheim.”