Lucien the hedgehog in the town of strange people

Schoolboy Artem Babakin was betrayed by his best friend. Upset, the boy decides to go swimming in a lake and invites his younger sister Dasha to come along. It's May, the temperature is about 100 degrees Fahrenheit, and the water should be just right. Once there, the brother and sister discover that no one else swims in that lake, even though it is the only body of water in the area. This is because a man recently died an unusual death in the reeds of this lake. After that, the heroes meet a talking hedgehog, and he immediately begins to suspect that something strange is happening in this town...