Olympic rowing hopeful and senior Metropolitan Police officer DCI Rebecca Meredith goes out alone to train on the river in Henley on a dark afternoon in late October - and doesn't return. When a desperate search by the police and a K9 team reveals the possibility of foul play, Scotland Yard wants one of their own on the case. Detective Superintendent Duncan Kincaid, returning from celebrating his marriage to long-time partner Detective Inspector Gemma James, is called to Henley to investigate. He soon finds that the world of elite rowing can be brutal, and that Rebecca Meredith's ex-husband was not the only person with good reason for wanting her dead.

Then, when a search-and-rescue team member is threatened, Kincaid realizes the case may be even more complex and more dangerous than he believed. But it is only when he enlists Gemma's aid that they find that the answers lie closer to home than they could have imagined - and are infinitely more deadly. It seems that more than one innocent life depends on their ability to track down the killer.