A group of Swedish tourists are on the way to a Russian village to witness the so called 'Festivity of Neptunus', in which the inhabitants take a dive in a hole in the ice. This tradition, however, does not exist at all. The inhabitants try to make a good impression by starting the 'tradition' to please the tourists.
Captain Emelin, nicknamed Emelya, Captain Vasin and Dolbunov are investigating the most complicated crimes, and criminologist Masha Likhacheva helps them in this. Emelya's reputation is so-so, the head of the department, Colonel Khitruk, dislikes him for his independent character, but has to put up with him because Emelya has a good disclosure.
