Professor Phillip Brainard, an absent minded professor, works with his assistant Weebo, trying to create a substance that's a new source of energy and that will save Medfield College where his sweetheart Sara is the president. He has missed his wedding twice, and on the afternoon of his third wedding, Professor Brainard creates flubber, which allows objects to fly through the air.

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.