Grace Winters is an uptight 72-year-old retired maths teacher who has been unable to enjoy life since the loss of her husband and son. When she receives a message that she has been left a house in Ibiza by a friend she hasn’t seen or heard from for decades, she decides to go and see it more out of duty than curiosity. The island’s hedonism and yoga retreats really aren’t Grace’s bag.

But when she gets to the Isla Blanca she finds that amid the bougainvillaea-strewn fincas, the partying and the pine trees, there is something else to discover – her own self-worth. Matt Haig likes to write about regret. His bestselling novel The Midnight Library , though ostensibly about depression, was really about the regret of the path not taken, its protagonist shown all the parallel lives she might have led, and asked if there’s one she’d prefer.

The Life Impossible is rooted in a similar place. Grace is so full of regret and self-loathing (over events that are slowly disclosed) that she has lived numb even to the possibility of happiness. This book, like The Midnight Library , also has a speculative edge, but it is far, far madder.

As Grace tries to find out what happened to Christina, the friend who left her the house but whose body has never been found, she acquires a posse of eccentric friends: a marine biologist who threw away his reputation for a preposterous theory; a world-famous DJ who inexplicably (and all too conveniently) overshares in a supermarket. Grace is expos.