This is an automatically translated description

The twins Sonia and Marko Bruma and their classmate Agava Medny have to fight evil in the real world, which is gradually being overrun by the Greys. First, it is the disgusting mathematician Kakuntsiya, and then the Grey Horse, who runs into the schoolyard and destroys everything around. He also tries to kill old Varvara, the grandmother with whom Sonya has become friends. After all, the grandmother has secret knowledge about the fantastic countries where Marko, Sonya and Agava have visited.

One day Varvara disappears, and the children realise that they have to save her. And also - to free their hometown from the Greys, where fear has settled and people have stopped laughing. Find out if the children will survive the battle between Good and Evil in the final book of Olga Maksymchuk's dilogy The World in the Volcano and Killer Rain.