It is difficult to solve crimes that are committed not on the usual city streets, but in the Siberian taiga! But Makar Veselov, his older sister Sonya and younger brother Ladoshka quickly get used to the harsh taiga conditions. To find an ancient manuscript that was considered to have disappeared without a trace, they have to make a dangerous raid along the banks of the Yenisei, navigate the taiga without a compass or map, and pursue the criminal through thickets and windfalls. It’s good that the guys are helped by their faithful friend, Honorik Nyuk, who feels at home in the remote wilds. But the honorik cannot catch the criminal red-handed... But his masters - real detectives Makar, Sonya and Ladoshka Veselovs - cope with this difficult adult task remarkably well!