An expedition of a few geologists is going to Siberia in order to found a gold sources during 1918.

Three friends in a summer camp are looking for a treasure hidden in a old mansion.

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.