Hosted by Truman Bradley, a 1940s film actor and former war correspondent, each episode introduced stories which had an extrapolated scientific, or pseudo-scientific emphasis based on actual scientific data available in the 1950s. Typically, the story lines related to the life or work of scientists, engineers, inventors and explorers. The program concentrated on such concepts as space flight, robots, telepathy, flying saucers, time travel, and the intervention of extraterrestrials in human affairs.

Airing a total of 78 25–26 min. episodes, the series was also known as Beyond the Limits in second run syndication during the 1960s and alternatively as Science Fiction Theater.

Opposite to what happened in the 1960s, the first season was filmed in color, but to cut costs the second season was in black & white. The producers had originally thought that color TV would progress faster than it did.