The twenty-year-old young man Sz. László is a lorry guard employed by an agricultural co-operative located in the vicinity of the capital. One day he neither posts the money officially entrusted to him nor goes to work, spending time and money as he likes on things he otherwise cannot afford, such as hanging around, sweets, driving in taxis, restaurants, Lake Balaton, girls, etc.

A female spy goes to Budapest to steal the plans of an anti-aircraft gun.