A mysterious potion switches the personalities of a buttoned up doctor and his laid back son.

Super Dave Osborne, our accident-prone stuntman hero, comes out of a self-imposed retirement to raise money for his new girlfriend's son's heart operation.

Dr. Jack Hammond has best chances to become medical superintendent in the clinic. So he's completely absorbed in his work and has no understanding for his teenage son Chris' problems with school. By accident one of them drinks a brain-exchanging serum, and it switches their identities. This leads of course to extraordinary complications in school and at work, but also to insight in the problems and feelings of each other.