The Secret in the Basement

What does the old Petersburg house conceal?
Summer vacations in Petersburg are full of surprises if you have strange neighbors and a treasure hidden somewhere in the house.
The adventures of Vlada, Dima, and Zamira continue!
They need to figure out why the new neighbor is fighting with everyone, what secret the girl named Stasya is hiding, and which house is depicted in the old painting. According to legend, a treasure is hidden in one of the walls of this house.
But it turns out that the treasures are not only being hunted by the three friends. The investigation becomes increasingly dangerous and interesting..