Star Trek: Season 1, Episode 27

The Alternative Factor (30 Mar. 1967)

TV Episode  |   |  Action, Adventure, Mystery
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Ratings: 5.9/10 from 1,067 users  
Reviews: 22 user | 12 critic

Existence itself comes under threat from a man's power-struggle with his alternate self, with the Enterprise's strained dilithium crystals presenting his key to a final solution.



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Title: The Alternative Factor (30 Mar 1967)

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Episode complete credited cast:
Janet MacLachlan ...
Charlene Masters
Richard Derr ...
Commodore Barstow
Arch Whiting ...
Assistant Engineer
Christian Patrick ...
Transporter Chief
Eddie Paskey ...


While investigating and scanning an uncharted planet, the Enterprise and its quadrant of space are subjected to a violent force that seems to cause a 'blinking out' of everything near them. When the scanners resume, where once there was no life on the planet, now there is one life sign. Kirk, Spock and a security force beam down to investigate and find a man named Lazarus who collapses and is brought aboard the Enterprise for treatment. To complicate things further, the initial phenomenon almost totally drained their dilithium crystals. Starfleet and Kirk suspect this phenomenon could be a prelude to invasion. While interrogating Lazarus he tells Kirk that he's locked in a struggle with another being who is 'anti life' and is behind the phenomenon. The disruptions continue to occur and the ship's situation grows worse. Written by tomtrekp

Plot Summary | Plot Synopsis


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Release Date:

30 March 1967 (USA)  »

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Aspect Ratio:

1.33 : 1
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Did You Know?


Actor Eddie Paskey appeared in 59 episodes of the original Star Trek (1966) series, 50 of them playing Lt. Leslie - a character name that came from William Shatner himself inserting his eldest daughter's first name (Leslie) into the show - but only in 'The Alternative Factor' does Eddie's role as Lt. Leslie ever appear in closing credits, and when it does - in contrast to the spelling by which it has become widely known and accepted - it is spelled L-E-S-L-E-Y. See more »


In the second sickbay scene, when Lazarus is on the bed, the amount and shape of the blood around Lazarus' mouth changes in each shot, alternately getting larger, then smaller, then larger, then smaller again, all within the space of less than two minutes. See more »


Dr. McCoy: He's in a lot of pain!
Capt. Kirk: Sometimes pain can drive a man harder than pleasure. I'm sure you know that, Doctor!
See more »

Crazy Credits

The closing credits are set against a combination background of stills from that episode and previous episodes. See more »


Referenced in Galaxy Quest (1999) See more »

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User Reviews

Worst episode of first season
1 December 2007 | by (United States) – See all my reviews

The storyline for "The Alternative Factor" is a great concept – the possibility of a negative parallel universe and a madman whose insane actions could lead to the destruction of EVERYTHING. But there are several aspects of this episode that really bother me, and IMHO, "The Alternative Factor" is the worst first-season episode.

I like the concept for this episode. I also like the dialogue between Kirk and Spock in the briefing room when they finally put all of the pieces of the puzzle together. But letting Lazarus roam freely about the ship is a flaw I can't excuse, and the final solution seems a bit drastic. I'm also not a fan of the special effects. For the most part, first-season episodes are pretty good, but this episode feels like it was put together in a big hurry. I'm giving "The Alternative Factor" a D grade and will find an alternative episode to watch when I can.

17 of 25 people found this review helpful.  Was this review helpful to you?

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