On the inaccessible Dragon Island, Athos Than organizes a martial arts tournament - an ideal chance for young fighters who would like to prove themselves, and Nathan Never, who is hired by the army to find a deadly bacteriological weapon...
The Hidatsa tribe chooses a new chief between two rivals. According to an old tribal custom, rivals compete in a game with seven arrows, but one of them is wounded, so Zagor takes his place.
Two evil scientists release mutated fish into a stream in the Hot Mountains. These fish are extremely aggressive and voracious... The ecological balance is disturbed, people are fighting for wells, and the Indians think that the Great Spirit is punishing