Nicolas Dickner, pictured. Photograph by Renaud Philippe.

Mary Hope Juliet Randall, called Hope, was the youngest member of a family that, for an indeterminate number of generations—some put the number at seven—had been afflicted by a serious obsession with the end of the world. The Randins, a family with vaguely Acadian roots, had been deported by the British in 1755. They landed in Maryland, adopted the name Randall—though without giving in to assimilation—and eventually returned to Nova Scotia, where they spent the ensuing decades squatting barren patches of peat bog.

In fact, the family obsession with the apocalypse might reasonably be traced back to that geopolitical trauma. Indeed, wouldn’t it be expected, or even inevitable, for a line of exiled farmers to be somewhat sensitive about urban sprawl, major disasters and the natural course of history? Yet there was no consensus around this theory, and ...