Convinced the report of a body on the beach is a false alarm, D S Cupidi darts to Folkstone with her daughter Zoe in toe to scan the area. But this time her instincts are off and it is Zoe who discovers Mimi Greene's body on the shoreline.

A regular wild swimmer with her friends, it is perplexing that she would have been out swimming alone, especially in bad weather. Putting aside her daughter's traumatised state, D S Cupidi must find the truth behind Mimi's death.

Meanwhile, Jill Ferriter receives a letter from a man named Stephen Dowles. Convicted of murder in the 90's, he's been in prison for more than twenty years. In the letter he claims to be her father.

Jill must lean on Bill South in the absence Cupidi, and finding out that he knew Stephen Dowles from a historic case, Bill sets out to uncover the facts around Dowles' conviction, revisiting old colleagues and criminals.