Fredek, a young inventor engineer, invents a "phone-televisor" (it's 1936). In addition to the troubles he causes himself with his invention, he wreaks havoc on the quiet, conservative life of the capital city. He finds his fiancée in an ambiguous situation, then the wife of the factory owner, to whom he wants to sell the invention, discovers her husband's betrayal. When installed in the restaurant, the invention exposes a web of lies and bad deeds. As a result, adventures, funny intrigues and conflicts give way to the idea of progress and youth's endless possibilities.