A couple of prospectors discover a strange old man more interested in plants than in a fortune in uranium. The episode touches on the classic fifties fear of nuclear apocalypse as the mysterious botanist states that nature has provided mankind with plants and now, having smashed the atom, mankind may destroy the plants and all of nature along with them. There is also a hint of environmental disaster as the stranger may come from a land where there are insufficient plants to procures life-sustaining oxygen Oddly the 'botanist' claims that plants create oxygen by process 'known only to nature' but by 1955, much of the photosynthesis pathway had been worked out and published (primarily by Melvin Keller, who won a Nobel Prize for the work in 1961). Truman Bradley introduces this episode with a brief history of the discovery of radiation, which is interesting but not overly related to the 'science fiction' aspect of the story. Pretty good SFT episode despite the pair of prospectors being clichéd (specially the 'tough guy') and the entire show occurring in the well-trodden Bronson Canyon. Lowell Gilmore, an American actor well known for affecting a British accent, does a nice job as the soft-spoken, erudite scientist.