It is the first thaw of spring and the body of a young woman surfaces in the River Thorne in the far north of Sweden.

Rebecka Martinsson is working as a prosecutor in nearby Karuna. Her sleep has been disturbed by haunting visions of a shadowy, accusing figure. Could the body belong to the ghost in her dreams? And where is the dead girl's boyfriend, also reported as missing the previous winter?

Joining forces once again with Police Inspectors Anna-Maria Mella and Sven-Erik Stalnacke, Rebecka is drawn into an investigation that centres on old rumours about a plane carrying supplies for German troops in 1943 that never arrived. Shame and secrecy shroud the locals' memories of the war, with Sweden's early collaboration with the Nazis still a raw wound.

And on the windswept shore of a frozen lake lurks a killer who will kill again to keep the past buried for ever beneath half a century's silent ice and snow.