“I have the key.” I pulled it out and was rewarded with the smallest hesitation from Larry before his grin broadened.

“Marvellous! Really marvellous. You’ve no idea how long I’ve been waiting to see that again.”

“Again?” I shook my head at his nonsense and turned to the professor. “Open!” I jabbed the key at the barrier . . . and found no resistance. The “pen” bounced once more and rolled under the armchair. Professor O’Kee tutted. He tapped the glass plate he had been looking at—across which lights and lines and numbers were moving in bright and colourful confusion—and turned, bending to retrieve the fallen pen, only to be arrested halfway through the action by the sight of three heathens from the savage north and a prince of Red March.

“Oh thank God!” he said. “Larry, put the kettle on.”

“We’re here to turn the Wheel off,” Snorri said. “Will the kettle help with that?”

“Of course you are.” The professor offered us a genial smile and nodded toward my still-outstretched hand. “You’ve brought back my key.”

“Your key? This is Loki’s key. It was made in Asgard.” Snorri bristled.

“I’m sure it was.” The professor nodded and hobbled to his armchair. He didn’t look well. “I’d offer you all a seat, but I’ve only the one I’m afraid. Age before beauty and all that.”

Larry, who had been standing at the desk back in the alcove now returned with a cup of steaming brown liquid. He offered it to the professor who took it in a hand that quaked with old-man’s palsy, threatening to slop the contents over first one side, then the other. He got it to his lips without incident and took a noisy slurp.

“That’s tea!” I said. The others looked at me.

“Well done, lad.” The professor took another slurp and made a satisfied “ah.”

I nodded my head curtly, accepting the praise. My mother brought the leaves of the tea plant with her from the Indus, dried and pressed, and used to drink an infusion of them in hot water.

The old man looked up at Snorri. “There’s no kettle, just a hot water dispenser and very old teabags. It’s an expression—language clings on to things long after we’ve forgotten what they were.”

“You say it’s your key,” Kara challenged.

“In a manner of speaking. In several manners of speaking in fact.”

“You’re Loki?” I asked, allowing just a hint of mockery into the question.

The professor shot me a look that had some steel in it, and, blowing on his tea, drank deeply. “I guess we should get to it. I can’t spend too long outside slo-time or the rats will get me.”

“Rats?” I glanced around.

“Yes. Can’t stand the things.” He put down his cup. “It’s what the part of my mind that wants to kill me summons up to do the job.”

“But we’re shielded down here? We can’t work magic like we could on the surface . . .” I looked back up at the tunnel mouth high in the wall, expecting to see Cutter John standing there with his pincers at the ready.

“There’s a dampening field, yes, but the, ah, the unfortunate sideeffects of the experiment can still manifest, they just take a little longer. Inside the slo-time bubble I’m completely safe, but too long out in the chamber and the rats start creeping in.”

“Larry was out here,” I pointed out.

“Yes.” The professor looked at Larry. The family resemblance was quite remarkable now the young man stood beside the professor’s chair. “Well, Larry . . . Larry is—”

“A marvellous mechanical man,” Larry said, and executed a sharp bow.

The professor shrugged. “I built Larry to carry my data-echo—he is, as he says, an automaton, housing . . . well, me, or at least the copy of me that the machines hold. We have our little joke: I’m the father—”

“I’m the son,” said Larry.

“And Loki is the Holy Ghost,” the professor finished.

“I don’t understand,” Kara said. None of us did of course, but the völva valued knowledge above pride.

“You’ve met Aslaug of course?” The professor struggled out of his chair, falling back once and waving off Larry’s help on his second attempt. The automaton—some sort of clockwork soldier, I assumed—gave us an embarrassed look. “A number of my contemporaries escaped their bodies when the nuclear strikes went in, both starting and ending the war over the course of a few hours. They were able, with the help of the changes that our work here had wrought on the fabric of things, to project their intellects into various different forms. Aslaug was Asha Lauglin, a brilliant physicist. She projected onto negative energy states in the dark-matter field. The projections all think they survived. They didn’t of course, Asha Lauglin was carbonized in a nuclear explosion. She died eleven hundred years ago. Aslaug is a copy, just like Larry here, only one that became corrupted over the years, caught up in the folklore of the people who repopulated. Reshaped by their beliefs and the joint will of the believers—”