Horneld's chronicles. Blue stone. Kashtanova Yu.

The company of friends is studying in the high school of the lyceum. Once a friend comes from distant abroad. But this friend turns out to be a native of another planet, which wages a long war with carriers of dark knowledge and their minions. And the distant planet needs the help of young earthlings, who themselves turn out to be descendants of aliens who once arrived on Earth with the mission of the world. Adolescents receive the mysterious blue stones as a “free gift”, which help them open the sleeping opportunities inherited by them. But it is unknown that for dangerous adventures they are waiting for them in front...