He lit an oil lamp and kept the windows covered. Candle grease smeared the panes. Only the faintest of shadows cast on the age-browned curtains allowed me to track him from the living room to the bedroom and back again. No smoke leaked from the chimney. The rooms would be damp and cold and half-heated by Calor gas. There was no electricity. If he cooked at all, it would have been in the living room. There were only two proper rooms, and a wooden washhouse tacked on the back – an ancient extension, perhaps once an elderly relative’s bedroom. Maybe it covered a well head. Maybe he drank his whiskey neat. Either way, he’d need to resupply before long.

At dusk he lit the lamp again.

He extinguished it at ten.

And rose at seven thirty.

Moss grew in the roof. Weeds tangled the kitchen garden. Garden trash was piled against the back door. The cottage was desolate, but not derelict – one of the few surviving remnants of a lost landscape of thatched poverty. Americans thought they were quaint. I thought they were more like millstones than monuments, tying us to a past that had got us where, exactly?

Here. Exactly.

I flexed my palm around the grip of the semi-automatic and focused on the rain-roar berating the headland.

The nearest house was five hundred metres to the north-east. It had been empty for a year – an unwanted holiday home languishing in negative equity. The track to its front door wound off to the main road four hundred metres further on. Seven hundred metres to the south-east a couple from Birmingham gazed out over Ulster in the midst of their retirement. Good luck with that. Drongawn Lough lay due south. Everywhere else was just rough sea or sodden turf.

I spent twelve hours in the gully. Out of habit I clicked a little pebble I’d picked off the beach against the back of my teeth. I didn’t need it: the rainwater kept my throat moist and my head clear.

It was a two-man job. But, as usual, I was flying solo: the details – and the consequences – were on me alone. While I’d snatched moments of sleep a night vision camera picked out in electric green the whitewashed walls of his self-imposed prison.

A week-long reconnaissance was just enough to establish a pattern of life, and short enough not to cause suspicion by hanging around: the target was secluded – no bystanders in the way and none to threaten the operation; the holiday park owners were glad to take a week’s rent out of season and asked no questions. If it blew up, there were only two people at risk: me and him.