The only episode of the original TV series that was not adapted was "Come Wander With Me," which was repeatedly postponed because it required actors who could sing. The show was eventually recorded in 2009 with husband-and-wife Marshall Allman and Jamie Anne Allman as the leads. Although producer Carl Amari praised the Allmans' performances, he had other issues with the episode, so it was scrapped. There were plans to record a new version, but it never happened before the series was canceled.
Although the scripts were faithful to the TV series, they had to be expanded (or in the case of season 4, condensed) to fit the 40-minute timeslot. Head writer Dennis Etchison studied the original teleplays and added dialogue and details that had been deleted whenever possible. A few shows heavily relied on visuals ("The Invaders," "Two," "Eye of the Beholder," etc.), so these were among the last to be adapted because they had to be extensively reworked for radio.
In addition to "The Time Element," the show's pilot which aired on the Westinghouse Desilu Playhouse, they adapted four teleplays from the original series that were never filmed: "Free Dirt," "Gentlemen, Be Seated," "Pattern for Doomsday," and "Who Am I?."
The producers pleaded with CBS to let them create some original stories, but the network was standoffish until they began running out of material. Ultimately, the network approved the production of 16 original stories: "The 25th Hour," "The Amazing Dr. Kyle Powers," "...And Cauldron Bubble," "Another Place in Time," "Beewinjapeedee," "Missing, Presumed Dead," "Mrs. Pierce Is Praying for Me," "The Nanobots," "Now You Hear It, Now You Don't," "Rest Stop," "Snow Angel," "There Goes the Neighborhood," "Ten Days," "The Time of Your Life," "Two Thousand-Twelve" (aka "2012"), and "The Walk-Abouts."
The show began airing on October 26, 2002, and generally played late on Saturday nights/Sunday mornings, often in a 2-hour block. Because it was syndicated, gradually picked up by new radio stations, and reruns were regularly mixed with the new episodes during its decade on the air, it's difficult to pinpoint precise airdates or episode order. The matter is further compounded by a vast assortment of CD, cassette, and digital releases in which episodes were presented in different arrangements.