Les Xipéhuz

It describes the fight that threatens humanity, in the beginning of its history, against a diffeent form of intelligent non-organic life, the Xipéhuz, some sort of sentient crystals.

This is followed by meetings of the clans and tribes, ritual sacrifices, and assembly of an army which is defeated by the Xipéhuz.

The second part is the memoir of a wise man Bakhoûn who observes the Xipéhuz from afar, then carefully approaches them to find out their habits and vulnerabilities.

The authors do not provide any additional information, merely noting the existence of this non-organic intelligence and its interaction with Neolithic humans.

"[2] In the 1980s, the name of the Xipéhuz was taken to designate an alien civilization in the universe of the French role-playing game Empire galactique.