Set on the fictional Caribbean island of Sans Amen, Roffey’s House of Ashes tells the story of three characters, a gunman, a hostage and a boy soldier, caught up in a botched coup d’etat. Cullin’s A Slight Trick of the Mind introduces a nonagenarian Sherlock Holmes. In the twilight of his life, as people continue to look to him for answers, Holmes revisits a case that may provide him with answers of his own to questions he didn’t even know he was asking – about life, about love, and about the limits of the mind’s ability to know. The authors talk to Georgina Godwin.