Kirk Wallace Johnson was waist high in New Mexico’s Red River fishing for trout when he first heard the bizarre story at the heart of this unusual and engrossing page-turner. He was using off-the-shelf flies: hooks wrapped in various materials to mimic the often-drab aquatic insects that trout feed on. His guide, Spencer Seim, showed him a home-made salmon fly, ‘one of the most strangely beautiful things I’d ever seen … It bore the feathers of a dozen different birds, flashing crimson and canary yellow, turquoise and setting-sun orange.’

Salmon flies, which resemble nothing in nature, are designed to provoke. The trout bites because it is trying to feed, the salmon because it is repelling a perceived threat. Seim explained that traditional Victorian salmon flies are ‘tied’ according to detailed ‘recipes’ created more than a century ago, often