The events of the detective series "Dangerous Cruise" revolve around a young girl named Lika Rakitina. Unfairly deprived of her job, she refuses to give up and decides to take revenge on her harmful and arrogant boss, Shelest. She learns that he is going on a cruise with his sweetheart... and she joins them on the ship. On the very first day, she manages to upset their relationship. However, Lika's triumph ends in tragedy: in her cabin, she discovers her murdered neighbor, and someone plants evidence in her purse.