Louie Kritski is a heartless landlord who has been so negligent in keeping up his ghetto apartment that he is threatened with jail time. The judge gives him another option -- he must live in his rat-infested hell hole until he brings it up to liveable standards.

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 complication...

Charlie Boyle finds that even his high IQ can't solve all of his problems when he takes on a double life in order to make friends his own age.