In a small English port town, adolescent Jonathan Osborne (Jonathan Kahn) and his widowed mother, Anne (Sarah Miles), lead a fairly predictable life until American sailor Jim Cameron (Kris Kristofferson) comes to town and sweeps Anne off her feet. Jonathan is wary of this intruder, but likes him in spite of himself -- for a time. It's only when Jim moves in permanently that Jonathan is pushed too far. With the help of a sadistic gang of neighborhood boys, he plots to eliminate Jim for good.