Planet Nghi-Ung-Liang is an evolutionary curiosity. The higher organisms living on it do not know the earthly division into two sexes, combining the characteristics of both in one body. The mating fight decides who will be the female and who will be the male - this is how the animals of this world live, and this is how the society of intelligent beings works. The planet is a real biological paradise... the work of earthly scientists is complicated by one thing: the crown of Ngi-ung-liang evolution, with all the fundamental physiological differences, is too similar to earthly man... The series is edited by Maria Rovna, cover design by Lyubov Pushkareva.