Behind the grinder is somewhere nearby. Krymov E.

They say that we do not know sufficiently even ourselves. Where to know another person! Katya could not imagine how many incredible secrets she keeps the inner world of her beloved grandmother. Thanks to the constructed supergenial scientist Denis, Katya and Kolya pass over the brink of human consciousness and find themselves in the whirlpool of fantastic adventures. Events in the story develop rapidly, and the plot is so captured that the book cannot be released from hands until the last page is read...

for the middle and senior school age.