A charter boat captain named John Nordley is hired by a man calling himself Mr. Anselm to transport him to Holland. That passenger, however, dies during the journey. When Nordley docks, he discovers the man was actually a Dutch policeman -- and that he was murdered. After meeting the victim's fetching daughter, Constanta, Nordley resolves to investigate the crime, hoping to discover the culprit who dared to kill on his boat.