Anne Osborne (Sarah Miles), a wealthy widowed Englishwoman running a high-end antique shop in Dartmouth, lives with her 13-year-old son Jonathan (Jonathan Kahn). Jonathan belongs to a secretive, nihilistic clique of schoolboys led by a charismatic fascist youth known as "Chief" (Earl Rhodes). When merchant marine officer Jim Cameron (Kris Kristofferson) arrives in port, he and Anne enter into a passionate, sensual erotic relationship. Jonathan secretly spies on their intimate encounters through a peephole in the wall. Initially idolizing Jim as a mythic romantic hero, Jonathan and his gang turn hostile when Jim decides to give up the sea, marry Anne, and settle into a routine domestic lifestyle. Viewing Jim's transition as a disgraceful betrayal of his heroic ideal, the boy clique plots a sinister, cold-blooded resolution to restore his honor.