Prokhor Lykov, nicknamed Vodyany in the village for his passion for fishing, always disappeared on the shore of the lake with a fishing rod. The chairman of the collective farm decides to use his enthusiasm in his own way ...

A spy game between Reds and Whites is in full motion during Russian Civil War.

Ten steps from the round pillar, in the ruins of the old fortress of Kum-Basan-Kala, secret messages are hidden, which must be delivered abroad. For these documents, foreign intelligence sends its spy. The film tells about the events that took place in the old fortress.