The flight was late leaving Houston Intercontinental. An O-ring on one of the ageing 747’s engines had to be replaced, and the engineers, worryingly, seemed to have trouble finding the right inspection hatch.

The seat next to Henry was occupied by a USAF airman who was stationed at a base in Suffolk. He was returning with his two kids from leave in Texas, and he was homesick before the Boeing left the ground. “The bathrooms in Britain are just disgusting. Even the hotels. They just never heard of sanitary seals. The Germans aren’t so bad with the bathrooms. But the French, my God, one place we stayed there was just a hole in the ground you were supposed to squat over…” Bathrooms on planes and on trains and in stations and in hotels, bathrooms in Britain and Italy and Greece and Sweden. It was, Henry realized with dismay, nothing so much as an asshole’s travelogue of Europe.

And after a couple of hours, the plane had metamorphosed, as ever, to a giant, stinking pig-pen in the sky, and every toilet Henry tried had a sticky floor and an overflowing trash can.

They flew out of bright morning light, from the west, towards Edinburgh. Henry peered out a window near the stewardess” station, and took his first look at Scotland.

He was descending into the Midland Valley, a broad belt of lowland that stretched from Glasgow to Edinburgh. This was actually what geologists called a graben: a rift, a block of land that had dropped between two faults. He could see the roads from England, to the south, sweeping down out of the hills to the valley floor, which was settled and arable, coated with picture-book fields and towns, though he could see, in some places, the scars left by Venus: failing crops, fields left brown and bare, a portent of troubled times to come.

But what made this valley different were the extinct cores of old volcanoes that stuck out of the ground, remnants of a volcanism spasm three hundred million years gone. The cones were an uncompromising demonstration of the old geologist’s saw that the stuff that’s left sticking out of the ground is harder than whatever has been worn away.

And as he descended towards Edinburgh itself he caught a glimpse of Arthur’s Seat, a composite volcano that was the greatest of the volcanic plugs; the buildings of the old city lapped around its flanks.

He landed at 7.00 a.m. local, having missed an entire night out of his life. A bright early spring day stretched ahead of him, and he felt like a piece of shit.

“The name’s Mike Dundas.”

The kid was waiting for Henry at the departure gate, when he finally got through queuing to have his passport checked.

Henry shook his hand. “We e-mailed. Good to meet you, Mike.”