About halfway across Lundy, if you’re trudging from the landing bay towards the north lighthouse, there’s a tiny holiday cottage all on its own. It’s a mile and three quarters from the island’s village and very basic inside. There are two bunks in the single bedroom; a dodgy oven in the kitchen that only works if you jam a wooden stick between the wall and the ‘on’ button; and, in the sitting room, the kind of gas lights that died out in the 1930s, because there’s no electricity — and so no wifi or TV — in the whole place.

In...