Pekka and Pätkä attempt to make a living as inventors. Accidentally they get involved in a bank robbery.
Scriptwriter Reino Helismaa was already fed up with the Pekka and Pätkä characters and originally wrote this story for characters called Julius and Jallu. Producer T.J. Särkkä didn't like these new characters and demanded the characters to be changed. And so was done and therefor this is the only Pekka Puupää film, which does not feature Siiri Angerkoski's notorious Justiina character.