 A spin-off from the "Armchair Theatre" anthology series, each episode was introduced by the actor Boris Karloff.Many of the episodes were adaptations of stories by science fiction writers including Isaac Asimov, Philip K. Dick and Clifford D. Simak.The series is described by the British Film Institute  as a precursor to the BBC science fiction anthology series "Out of the Unknown," which was produced by Out of This World creator Irene Shubik after she left ABC.