“Got an email this morning,” she tells me. “Actually Gerry Lockhart forwarded it on Friday evening but we’d already left the office and Facilities were taking the mail server down for maintenance.” I startle guiltily: that was probably me, going through the server logs with fire and the sword in search of Pete’s joker. “Calm down, Bob, it’s not OpExec this time. Turns out the negotiation team for BLUE HADES—it’s the once-a-decade Benthic Treaty renewal fish-fest—are down one sorcerer: Julie Warren’s got pneumonia, so Gerry asked me if I could go along to bulk up the front-facing team. You know how They get if They think we aren’t taking Them seriously.”

They are the Deep Ones, the ancient alien water-world types who own about 70 percent of the planet’s usable surface area (the bits that are below the crush depth of our nuclear-powered submarines). We have an agreement with them: we agree not to piss them off (by, for example, building the Underwater City of Tomorrow! or otherwise intruding on their territory without prior arrangement) and they agree not to exterminate us. The bilateral agreements need to be renewed regularly by just about every nation with a coastline and a submarine, and BLUE HADES tend to get stroppy if they think we’re taking the piss or getting blasé about them. So every decade a bunch of our more powerful occult offensive operatives get to hole up on a disused North Sea accommodation rig and play bodyguard to the folks from the Foreign Office (Non-human Affairs Department).

“How long are you going to be gone this time?” I ask, relaxing slightly.

“I have to be on a chopper out of RAF Lossiemouth at about six o’clock tomorrow morning, which means catching the morning flight to Aberdeen, then an onward flight this afternoon. Then I’ll be with the negotiating team for, hopefully, a day or two, and back home again. Don’t worry, love, I just have to hang around and look professionally formidable.”

“But if things go wrong—”

“I said don’t worry, dear. Nothing is going to go wrong.” She smiles at me, a trifle sadly.

“But—” I shut up.

What she actually means is that everything will be all right unless someone on our team fucks up and offends BLUE HADES so badly that no conceivable apology is acceptable. In which case, the first we’ll know about it is when the Storegga Shelf and Cumbre Vieja simultaneously collapse. You won’t be reading about it in the newspapers because the combined hundred-meter super-tsunamis will wash the British Isles clean (killing everybody who lives within a hundred kilometers of the coast on both sides of the North Atlantic, just for an encore). The devastation will make a strategic nuclear war look like a lovers’ quarrel.