I picked up Catriona Ward’s labyrinthine thriller Sundial at 11pm on a Sunday, intending to read a chapter or two before bed. Three hours later, I was breathlessly devouring the last few pages. As a word, ‘unputdownable’ is both ungrammatical and overused, but there is no better description of Ward’s gloriously gothic new novel. The book is grotesque from the outset, as we meet Rob and her husband, Irving, who inhabit a horror story of a marriage. Why does Rob tolerate Irving’s philandering and physical abuse, not to mention his pandering to their eerie eldest, Callie, and her unhealthy preoccupation with what is dead – or, as Callie puts it, ‘pale’? He must, we think, know something about Rob that we don’t.

As the story unfolds, we learn about Rob’s upbringing with her sister at Sundial, a remote ranch in Arizona. Her youth resembles more a sojourn on the island of Doctor Moreau than a conventional American childhood. Intertwined with the core narration provided by Rob, in which she travels