The action takes place on Earth, on a space interplanetary base and on the planet Ritoki. The main character - Denis Novikov - learns that he has the rarest mutation: the so-called Arena gene is present in his genome. The body of the owners of such a mutation does not reject the Rowwall bacteria, which repeatedly enhance the physical capabilities of their carrier. Denis ends up at the base of the vestiars, where he is endowed with these bacteria. He later chooses, or rather, is chosen by swords created from Olun wood, capable of transmitting the symbiote. The main goal of the Arena is not only to identify the strongest, but also to constantly strengthen the participants, which makes the fights in the Arena unpredictable. Meeting with May, a humanoid mentor at an alien base, a Facebook curator on Earth, strange Vestiars. What will help and what will prevent Denis from participating in the Arena, what trials thanks to them he will be able to go through, and what will hinder him in this. And why do invincible Vestiars need it?