The third book in the Arcanum series. The beaches and embankments of New Ingersham are crowded with vacationers, there are no empty seats in the cafe. Neither locals nor tourists are even aware of what is happening next to them. Meanwhile, ancient legends come to life - a terrible tribe of Gorgonids led by Euryale is preparing to capture New Ingersham, and then the whole world. True, for this they need the help of Lera and Maxim. But what can connect two ordinary teenagers with the monstrous tribesmen of the Gorgon Medusa? And why are the members of the banned Extropolis corporation hunting for the guys? Probably only the insidious cunning and eternal adventurer, the unsinkable Ippolit Bestuzhev, knows about everything.