Cambridgeshire, September 1813: Detective Stephen Lavender and Constable Ned Woods are lured to an isolated estate in the deadly marshland surrounding Ely, to investigate a murder. But nothing is as it seems at the mysterious Willow Marsh Manor. They soon realize they've come across this feuding family before - in the direst of circumstances. With no dead body and no sign of the woman who summoned them, Woods fears someone has planned a murderous revenge. Meanwhile, Lavender dreads the disclosure of his greatest secret. A secret that, if revealed, will destroy both his career - and his relationship with Woods. Haunted by ghosts from the past, Lavender and Woods must tread a careful path through this watery and dangerous terrain in order to solve one of the most perplexing mysteries of their career.