The weekend at the Dubovaya Griva tourist center was overshadowed by the death of one of the vacationers, a pretty young woman. Svetlana was found in the river under the pier: she either drowned or was killed by someone. In any case, an expensive ring with a large sapphire disappeared from her hand - so they were hunting for it? Or is it something completely different? Private detective Tatyana Ivanova, who by the will of fate turned out to be a participant in the events, undertakes to find out why the young woman died. By pulling a thread, the detective unraveled a tangle of riddles and secrets that would be enough for a dozen crime stories...