Nathan Forrest is a lapsed Catholic, a welder, an illegitimate son, and a gifted jazz trumpeter. After he begins pursuing Dorothy - a Protestant girl from a middle-class family - they face the antagonism of mid-20th century Scotland. Against a backdrop of decaying Westburn's doomed shipyards and bitter environment, the young lovers seek to escape the contraints of prejudice and hate. But is their love and determination enough to bring them happiness, or will religious and social conflict consume them both?