The planet Ngi-Ung-Liang is an evolutionary oddity. The highest organisms living there don’t know the Earth division into two sexes, combining traits of both into a single body. A mating duel determines who will be female and who will be male. That’s how the animals of this world live; the society of intelligent beings is organized the same way. The planet is a true biological paradise… but there’s one complication for Earth scientists: the crown of Ngi-Ung-Liang evolution—despite all the fundamental physiological differences—turns out to be too similar to a human from Earth…