The Young Adam screenplay is based on the 1954 novel of the same name by Alexander Trocchi. The drama begins with the discovery of a half naked woman's corpse by two barge workers, Joe (Ewan McGregor) and Leslie (Peter Mullan).
A young drifter, Joe hoists the body ashore calmly, and soon after, police investigations find a suspect and charge him with murder. Joe shares the living quarters on the barge with Les and his wife, Ella (Tilda Swinton) and he begins a torrid affair with her.
Joe is an erratic and amoral character who knew the dead woman and the circumstances of her death but will not reveal the truth to anyone.