Young Adam (2003)

Joe, a rootless young drifter, finds work on a barge travelling between Glasgow and Edinburgh, owned by Les and his wife Ella. One afternoon, they discover the corpse of a young woman floating in the water. As the police investigate and a suspect is arrested, it becomes clear that Joe knows more than he's letting on. Flashbacks reveal Joe's past relationship with the dead woman, Cathie, while his current illicit affair with Ella heightens tensions on the barge.