Alastair Cunningham wakes up in hospital with almost total amnesia. But he knows that something terrible happened in his past, something that haunts him still. A young family friend, Clémence, is called in to help rekindle his memory. Retreating with Alastair to his remote cottage by a Scottish loch, Clémence finds a peculiar manuscript hidden away from prying eyes. Reading the prologue, she discovers a murder by someone very much like a young Alastair. The victim? Clémence's grandmother, Sophie. Could this kindly old man truly be a killer? Clémence becomes determined to find out what happened all those years ago, even if she must risk everything to do so...