Simon Serrailler is faced with that most complicated of investigations - a cold case. Freak weather and flash floods all over southern England. Half of Lafferton is afloat. A landslip on the Moor has closed the bypass and, as the rain slowly drains away, a shallow grave - and a skeleton - are exposed. It doesn’t take long to identify the remains as those of the missing teenager, Harriet Lowther, last seen carrying a tennis racket while waiting for a bus. But that was 16 years ago.
The first message sent to Tom Thorne's phone was just a picture - the blurred image of a man's face, but Thorne had seen enough dead bodies to know that the man was no longer alive. But who was he? Who sent the photograph? And why? While the technical experts attempt to trace the sender, Thorne searches the bulletins for a reported death that matches the photograph. Then another picture arrives.