A professor who wrote a book about cavemen, his students suspect he is the caveman.

High school misfits Stoney and Dave discover a long-frozen primeval man buried in their backyard. But the thawed-out Link—as the boys have named him—quickly becomes a wild card in the teens' already zany Southern California lives. After a shave and some new clothes, Link's presence at school makes the daily drudgery a lot more interesting.