The Xhroll, an alien humanoid race whose infertility is bringing them near extinction, come into contact with a crew of fertile human astronauts. Their encounter on a remote space station will have significant consequences for both species when a human male winds up impregnated.

Author Elia Barceló's setup is funny and feminist, and it raises questions of what it means to be "male" or "female"—prescient, considering this novel was first published twenty-five years ago. The anniversary is being celebrated now with the first English-language edition, translated by veteran sci-fi translators Yolanda Molina-Gavilán and Andrea Bell, who also provide a critical introduction.