When I lay it out like that we sound like some kind of superhero team, don’t we? But we’re actually just a couple of married civil servants with day jobs that involve far too much paperwork, and the occasional terrifying incursion from another dimension. And we’re probably doomed, but I’ll get to that later.

• • •

AN EARLY AUTUMN EVENING IN CENTRAL LONDON CAN BE A FINE experience, or a lousy one. It depends on a variety of factors: on the weather, on whether you’ve just been sucked into a bad-tempered and pointless argument with your wife, on how worried you are about next month’s credit card bill. Not to mention your uneasy anticipation of the meeting your new and somewhat unpredictable manager has scheduled for tomorrow afternoon.

That night I’d rolled ones on all of my dice: it was raining and gray, Mo was pissed off with me, the credit card bill was unpleasantly large, and Lockhart isn’t the world’s most forgiving boss. So I escorted Mo to the nearest tube station, then, rather than accompanying her home in prickly silence, I made a lame excuse and headed back to the office—not knowing that I was about to put myself in mortal danger.

• • •

I WORK IN A BUILDING CALLED THE NEW ANNEX. IT’S A LUMP OF mid-seventies concrete brutalism that squats above a closed discount store somewhere south of the Thames. The New Annex is one of the temporary offices we occupy while a public-private partnership rebuilds Dansey House, our headquarters building. Thanks to the current government’s budget cuts, the months have turned into years and the Dansey House rebuild appears to have stalled. Turns out there’s a nagging problem with long-forgotten and extremely powerful geases mucking up the foundations: we’ve run into the thaumaturgic equivalent of trying to rebuild a university campus and discovering that the walls are riddled with asbestos, the chemistry department used to pour mercury compounds and radioactive waste down the drains, and the admin block was built on top of a plague pit full of skeletons.

I’m resigned to working in the New Annex until I die. It wasn’t furnished for comfort or convenience, even by civil service standards—nobody expected to be there more than six months—and these days it’s just seedy, with peeling paint, cracked plaster, grubby uncleaned windows, and a persistent whiff of sewage in the basement levels.

• • •

THERE IS AN ENTRYPHONE BY THE SIDE DOOR TO A SHUTTERED discount shop in London. It looks abandoned, but works just fine: it’s our staff entrance. I stepped inside, pulling out my LED Lenser torch. “Hello?” I called.

Something hissed in the darkness nearby.