Two apartment house dwellers, although unrelated, share the same name. One is an older man with an appreciation for and love of classical music, while the other is a younger man addicted to swing music. The niece of the older man arrives for a visit and gets into the wrong apartment. Complications arise.
A spy film about Professor Skalski's invention - rays that could stop engines, thus avoiding wars - which becomes the focus of foreign intelligence. In order to take over the discovery, a secret agent is sent to reach the invention via the professor's son.