 Jean Novak, neglected by her brutal and alcholic mechanic husband Stan, persues affairs with other men. One of them is Stan s best friend Eddie, whom she falls in love with. When Eddie wants to break it off with Jean, she resorts to underhanded tactics to continue seeing Eddie by introducing Stan s unmarried younger sister Ellen, to Eddie and trying to break them up. But when Stan finds out that Jean is neglecting their three-year-old son for drunken binges and sex parties, he goes over the deep end and sets out to stop Jean, for good.