The sisters Kisonka and Murka have a famous surname - Kosinsky. An entire half-paragraph is dedicated to their ancestor in the history textbook! Therefore, when an announcement about a summer vacation combined with the search for Kosinsky’s treasure appeared on the forum of the descendants of the famous hetman, the girls could not pass by. And now the sisters meet other heirs, anticipating the summer with a slight hint of excitement, but it turns out that for some people the treasure is really real, and these mysterious people are ready to do anything to remove their competitors... Only Kisonka and Murka are not ordinary girls, and the detectives are from the White Goose agency, and they are ready for any adventure!