A young drifter named Joe (
Ewan McGregor) finds work on a barge owned by the down-to-earth Les (
Peter Mullan) and his enigmatic wife Ella (
Tilda Swinton). One afternoon Joe and Les happen upon the corpse of a young woman floating in the water and the questions begin. Accident? Suicide? Murder?
As the police investigate the case and a suspect is arrested, it becomes evident that Joe knows more about the drowned woman Cathie (Emily Mortimer) than he will admit. Meanwhile, against the backdrop of the investigation, Joe and Ella embark on a passionate affair.