When Herman and Grandpa go to the bank to make a withdrawal, they are mistaken for bank robbers and handed eighteen thousand dollars in cash. When Herman gets home and realizes the wrong he's done wrong, he can't rest until he returns the money. When trying to bring it back in the middle of the night, Herman and Grandpa wind up locked in the bank's vault.
Elenco: Fred Gwynne , Yvonne De Carlo , Butch Patrick , Al Lewis , Beverley Owen , Pat Priest .