"This star shall be free by Murray Leinster" is a science fiction short story written in the mid-20th century. It follows an alien ecological experiment imposed on prehistoric humans, using advanced tools and a compulsion device to explore how abundance and technology might reshape a species and its future, with themes of unintended consequences and cultural acceleration. A young cave-dweller named Tork is drawn by an alien ship’s mind-urge to its landing site, where water-dwelling Antareans gift him a device that summons living creatures and simple but transformative weapons like flint-tipped spears, knives, and bows. The tribe feasts, spreads the tools, and chaos follows as others covet the new power. When theft hits home, Tork cleverly retunes the summoning device to the aliens themselves by drawing their likeness on cave walls, trapping the ship until it trades more tools for the destruction of those images—accidentally launching the tradition of cave art and cementing humanity’s rapid rise. Millennia later, the aliens return to colonize Earth’s oceans, only to be annihilated by the now spacefaring descendants of those cave-folk, revealing the long arc of consequences set in motion by one “kind” experiment. (This is an automatically generated summary.)