Moon-Watcher Timeline and Summary

Moon-Watcher lives in the dim distant past among the man-apes.
It's a bad season, berries and food are scarce.
A space slab lands and uses mystic space powers to try to get the man-apes to think and evolve.
Moon-Watcher is a smart man-ape and figures out how to use simple tools.
He uses the tools to kill a pig, and generally teach the tribe to hunt, vastly increasing their food supply.
He also kills a leopard. Then he kills the chief of a rival tribe. Progress means lots of killing.
Moon-Watcher is lord of all he surveys. Eventually his descendants become human beings and rule the world. Happy man-ape.