Professor Ned Brainerd (Fred MacMurray) is hot on the discovery of a new substance. He found great success with his first discovery of Flubber and is now working on dry rain. But the ease with which Flubber was discovered is not the case with his dry rain. No one seems to think it can work and to top it off, dry rain has disastrous side effects. His wife Betsy (Nancy Olson) is getting rather tired of all the turmoil that is going on in her home. What Brainerd doesn’t count on is that Flubbergas, which is made from the leftover Flubber, is actually quite a discovery. Now Brainerd must figure out how to prove that dry rain will work and that Flubbergas may have a purpose as well.