‘Gradually, then suddenly’, according to Ernest Hemingway, is how a man goes broke – and it’s also how society falls apart when insomnia claims the world. Anyone who can still sleep is in danger, as insomniacs are driven into a rage at the sight of another sleeping.

Black Moon follows a disconnected band of sleepers: owl-masked teenager Lila; Chase, looting chemists for drugs; Biggs, trawling the city for his missing wife; Felicia, searching for a cure at a sleep research lab.

Although the source is insomnia rather than a virus, this is a zombie story in all but name. Calhoun’s choppy style of switching between characters and places won’t be to everyone’s taste, but it works perfectly for the subject matter. What better way to show the disconnection we feel when we haven’t slept? Considering its vast canvas and exciting subject, it’s no surprise that the novel has already been optioned for film.

Black Moon is a thoughtful, literary survival tale that will appeal to fans of Peter Heller’s The Dog Stars and Karen Thompson Walker’s The Age of Miracles.