A Wrinkle in the Skin (aka The Ragged Edge) is a 1965 post-apocalyptic science fiction novel written by the British author Samuel Youd under the pen name of John Christopher.

A massive series of earthquakes on a worldwide scale reduce cities to rubble, plunging survivors into barbarism. Most of western Europe is dramatically uplifted, transforming the English Channel into a muddy desert, while elsewhere lands are plunged below sea level and flooded.

The protagonist is Matthew Cotter, a Guernsey horticulturalist who finds himself one of only a handful of survivors on the former island. Cotter decides to trek across the empty seabed to England, in the faint hope his daughter has somehow survived.