July 1976. Steelworker Trevor Harding stumbles upon a faded photograph of his beautiful young neighbour, throwing his humdrum life into turmoil. Convinced she’s being exploited by a former boyfriend, Trevor hatches a plan to rescue her – but things soon spiral dangerously out of control.
As a heatwave grips South Wales, his wife Sylvie is forced to confront her own past, while their daughter Karen fears her cowardice may have led to murder.