The Criminal and the Lady(1963)

Original title: Zbrodniarz i panna

Young Małgorzata leads a very boring life as a cashier. One day a robber riddles her bank car with bullets, kills the driver and two security guards and takes the money. The police finds out that the stolen banknotes are being spent at a fashionable spa resort. The only way to find the criminal is to favor Małgorzata with a seaside holiday in the company of a handsome Captain as her brother.