|The Alternative Factor|
|Season 1, Episode 27|
|Air date||March 30, 1967|
|Written by||Don Ingalls|
|Directed by||Gerd Oswald|
|Errand of Mercy||The City on the Edge of Forever|
|Star Trek episodes|
The Enterprise investigates a planet after a solar system wide disturbance sends shock waves throughout the Federation.
Stardate: 3087.6 - 3088.7 The non-existence. It hurts! The non-existence. It hurts!
The Enterprise is ordered by Star Command to investigate a phenomenon after the universe goes into a state of "non-existence" for a moment. They trace the source of the phenomenon to a nearby dead planet that they are orbiting. Kirk and a group beam down to the surface. There, they find a man named Lazarus, who is chasing after an unknown being. After Lazarus faints, Kirk takes him aboard the Enterprise, the crew realizes that Lazarus is exhibiting strange behavior. At one moment he is sane and calm. Then at other moments, he is exhibiting violent rage. Lazarus overhears two crewmen talking about the ship's dilithium crystals, which power the ship. Lazarus breaks into the engineering room and steals the crystals. Then after being taken for questioning by Kirk, Lazarus escapes the ship and beams down to the planet. On the planet, he attempts to use the crystals to power his ship. It is not long before Kirk beams down to the planet and confronts him. The Enterprise fires its laser The Enterprise fires its laser
Kirk soon learns that there is two version of Lazarus, a mad one from an anti-matter universe and the sane from Kirk's universe.. The sane Lazarus explains that the mad Lazarus is trying to cross over to Kirk's universe and hat both universes would be destroyed if he succeeds because there can only be one Lazarus in the universe. Kirk finds the mad Lazarus and helps the sane Lazarus trap in a time corridor. Trapped in the corridor the mad Lazarus is unable to destroy the universes, but the sane Lazarus is also trapped with him until the end of time.
The role of Lazarus was originally given to John Drew Barrymore. However, the actor had failed to show up for the shooting and Robert Brown was given the role instead. Because of John Drew Barrymore's absence shooting for the episode was 2 days over schedule. The producers of Star Trek filed grievance with the Screen Actors Guild and Barrymore's SAG membership was suspended for 6 months