The Alternative Factor

"The Alternative Factor"
Star Trek: The Original Series episode
Episode no.Season 1
Episode 27
Directed byGerd Oswald
Written byDon Ingalls
Featured musicAlexander Courage
Cinematography byJerry Finnerman
Production code020
Original air dateMarch 30, 1967 (1967-03-30)
Guest appearances
  • Robert Brown - Lazarus
  • Janet MacLachlan - Lt. Charlene Masters
  • Richard Derr - Commodore Barstow
  • Christian Patrick - Transporter Chief
  • Arch Whiting - Assistant Engineer
  • Tom Lupo - Security Guard
  • Ron Veto - Security Guard
  • Vince Cadiente - Security Guard
  • Eddie Paskey - Lt. Lesley
Episode chronology
← Previous
"Errand of Mercy"
Next →
"The City on the Edge of Forever"
Star Trek: The Original Series season 1
List of episodes

"The Alternative Factor" is the twenty-seventh episode of the first season of the American science fiction television series Star Trek. Written by Don Ingalls and directed by Gerd Oswald, it first aired on March 30, 1967.

In the episode, the crew of the USS Enterprise encounters a "reality jumping" madman. It is the first Star Trek episode to deal with a parallel universe.[1]

  1. ^ Myers, Eugene; Atkinson, Torie (2009-07-08). "Star Trek Re-watch: "The Alternative Factor"". Tor.com. Archived from the original on 2021-05-09. Retrieved 2022-07-08.