Synopsis by Hal Erickson
This time, the IMF takes on the challenge of staging an invasion from outer space. It is all part of a plan to derail the political ambitions of mob-connected publishing tycoon Edward Granger (Steve Forrest). Highlights include Phelps and Casey's pose as a pair of futuristic physicians. Written by Harold Livingston, "The Visitors" was originally telecast November 27, 1971; ironically, the episode was rerun during the same April week in 1972 that the Apollo 16 lunar expedition was launched.