Young Cossack Ivan Platov ends up in a secret detachment of spies, making full use of his gift of character - a person with very strong extrasensory abilities that have an “applied” combat purpose. But at the very beginning of his military journey, Ivan finds himself drawn into a series of strange events, where the interests of unknown foreign intelligence, emissaries of the Moscow Tsar and Crimean slave traders are intertwined. The situation is heating up, and clouds are gathering over Ivan’s head. In order to protect him from the machinations of his enemies, and at the same time take advantage of the current situation, Ivan is sent to the Crimean Khanate as an illegal intelligence officer. Don Cossack Ivan Platov turns into the Ottoman youth Hassan. But fate does not leave him alone here either. Navigator Hasan becomes a sailor in the Ottoman Empire fleet.