A random companion of young adventurers - schoolchildren, Fedya Chudintsev and Petka Kochetkov, who went to Crimea without the knowledge of their parents, invites them to find the treasures of the ancient king Mithridates. Giving their consent, the guys had no idea that the search for the treasure would result in imprisonment for them in the Kerch quarries and only Fedya’s ingenuity, coupled with the methods of Sherlock Holmes and Hercule Poirot, would help out their friends this time...