Spain, 2020. When ex-pat fugitive Jack Cleland watches his girlfriend die, gunned down in a pursuit involving officer Cristina Sanchez Pradell, he promises to exact his revenge by destroying the policewoman Cristina's aunt Ana has been deaf-blind for the entirety of her adult life: the victim of a rare condition named Usher Syndrome. Ana is the centre of Cristina's world, and of Cleland's cruel plan. John Mackenzie, an ingenious yet irascible Glaswegian investigator, is seconded to aid the Spanish authorities in their manhunt. He alone can silence Cleland before the fugitive has the last, bloody, word.