Misty School. Let's Play! Book 3

Once, an unusual egg appeared on Mia's desk. Inside, someone was laughing very strangely! These sounds had been heard by no one except Mia and Kulyachok. If any of the classmates took the egg, the next day it would invariably be back on Mia's desk. And the strangest thing was that since the day the girl discovered the egg, students had begun to disappear from her class. What is this - some kind of game or are STRANGENESS happening again?.. Mia has no idea that she is about to uncover the most important secret of the Misty School...