John Christopher (the best-known pseudonym of Sam Youd) made some great achievements in the so-called young adult category. Here he plants his flag in the adult section of the library.

"A Wrinkle in the Skin" follows the format of the post-apocalypse sub-genre, but it goes deeper than most. The title alludes to the small changes on the surface, but the black heart of humanity is the real subject here.

The disaster which wipes out most of the population is an unexpected, planet-wide earthquake. Its cause is unknown, its effects so devastating that every building on earth is destroyed, whole landscapes transformed, oceans drained. The protagonist, Matthew Cotter, sets out from the Island of Guernsey, clawing his way through the devastation, to find his daughter. On the way he discovers that, far from coming together to keep the spark of humanity alive, the traumatised survivors have turned to barbarism, rape and murder.

Unlike the empty cities and plentiful bounty of other fictional apocalypses, this one leaves a harsh and hostile land, where crops and animals have been churned into mud by the cataclysm. Even the tinned food has been buried, forcing the survivors to dig with their bare hands in the hope of finding a meal of baked beans and condensed milk.

Matthew encounters more than one shattered survivor who has succumbed to religious fervour, believing the geological reality of "the Bust" to be a divine punishment, the arrival of the end times. He is much better at diagnosing their madness than he is at recognising his own delusions.

After a few dozen pages of the relentless descriptions of the horror visited on the earth, I felt like I too was transported into a sort of revelation, a journey into the heart of darkness, perhaps. There are also strong echoes of Cormac McCarthy's "The Road", which post-dates "A Wrinkle in the Skin" by three decades. The biblical allusions are perhaps less elegant than those in "Earth Abides" by George Stewart, but overall I feel like John Christopher has made it into the upper echelons with this book.

Inevitably I must also compare "A Wrinkle in the Skin" to John Wyndham's "The Day of the Triffids". That more famous work always invites the reader to cheer on the survivors who choose altruism, who trust in the best of humanity, and vanquish the tyrants and looters. You always feel you are along for the ride, that if it came to the crunch, you'd be one of the good guys, siding with Mason and Coker against the killer walking plants and the clueless humans who are doomed to become their fertiliser.

By contrast, John Christopher isn't saying the psychopaths will inherit the earth, but a hopeful future isn't guaranteed. You have to fight for it, and at every stage there's a real chance the dark side will overwhelm you.