Mishka and Romka are true friends; they study in the fifth grade of a regular Moscow school. They walk together, cheat on tests, misbehave, and pull girls’ pigtails. During recess, the boys sneak into the physics laboratory, where there is a curiosity - a glass machine. Their classmate sneaks up on them and stuns Romka with her briefcase. A fight ensues. Flasks and test tubes are flying from the table. A jar of pink liquid falls on the children and they become small, smaller than a grain of sand. The car is also shrinking in size. Two unfortunate children end up on the floor, where at any second they could be crushed by their classmate’s sneakers.