I take a breath, step down onto the concrete, and try to minimize my movements as I go looking for the Cosford service. I find the platform it stops at: a crumbling concrete strip opposite a peeling wooden fence. The rails are rusty and overgrown, and a couple of young trees are trying to colonize the tracks; but the TV screen overhead is lit up and predicting a train will be along in ten minutes. I take a shallow breath and sit down, hunching instinctively towards the nearest shade. Fifteen minutes later, the TV screen is still predicting a train will be along in ten minutes; then my mobile rings. It’s Mo.

“Bob!” She sounds so cheerful when she says my name: I don’t know how she does it, but it cheers me up.

“Mo!” Pause. “Where are you?”

“I’m back in the office! I spent most of the morning in the stacks, I only just got your text…” The one telling her I was off on a day trip to Cosford. The Laundry’s deep archives are in a former underground tunnel, way down where the sun doesn’t shine, and neither do the cellular networks.

“Right. I’m on a railway platform waiting for an overdue train. It’s about two hundred degrees in the shade, the pigeons are falling out of the sky from heatstroke, and nobody will sell me a beer.” (Well, they might if I’d asked for one, but…)

“Oh, good! When are you going to be back?”

“Sometime late this evening,” I say doubtfully. “I’m due to arrive in Cosford at”-I check the lying timetable-“two thirty, and I don’t think I’ll get away before six. Then it’ll take me about three hours-”

“Angleton did this? He did, didn’t he!” Suddenly Mo switches from warm and cuddly to spiky as a porcupine: “Didn’t you tell him you couldn’t? We’re supposed to be having dinner with Pete and Sandy tonight!”

I do a mental backflip, re-engage my short-term memory, and realize she’s right. Dinner for four, booked at a new Kurdish restaurant in Fulham.