The fifth-grader Borya, a fidget and an inventor, was appointed a counselor in the first class. Not taking this at first seriously, the boy gradually became interested in new and unexpected duties for him.
A Red Army officer Polevoy possesses a navy dirk with a secret message encrypted in its handle. The second part of a message belongs to a White army officer Nikitskiy. It's up to three young friends of Polevoy to uncover the mystery.
