Star Trek: Season 1, Episode 27

The Alternative Factor (30 Mar. 1967)

TV Episode  |   |  Action, Adventure, Mystery
Your rating:
    1 2 3 4 5 6 7 8 9 10 -/10 X  
Ratings: 5.9/10 from 1,109 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.



, (created by)
Watch Episode
0Check in

Watch Now

Free at IMDb


Celebrate IMDb's 25th Anniversary with Photos We Love

IMDb turns 25 on October 17! To celebrate, we put together a gallery of some of our favorite movie, TV, and event photos from the last 25 years.

See the Photos We Love

User Lists

Related lists from IMDb users

a list of 1494 titles
created 14 Jul 2012
a list of 25 titles
created 19 Mar 2013
a list of 44 titles
created 03 Jun 2013
a list of 30 titles
created 11 months ago
a list of 29 titles
created 6 months ago

Related Items

Connect with IMDb

Share this Rating

Title: The Alternative Factor (30 Mar 1967)

The Alternative Factor (30 Mar 1967) on IMDb 5.9/10

Want to share IMDb's rating on your own site? Use the HTML below.

Take The Quiz!

Test your knowledge of Star Trek.
« Previous Episode | 28 of 80 Episodes | Next Episode »





Episode complete credited cast:
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


See all certifications »


Official Sites:



Release Date:

30 March 1967 (USA)  »

Company Credits

Show detailed on  »

Technical Specs


Sound Mix:


Aspect Ratio:

1.33 : 1
See  »

Did You Know?


This takes place in 2267. 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 »


Capt. Kirk: You'll be trapped inside that corridor with him forever. At each other's throats throughout time.
Lazarus: Is it such a large price to pay for the safety of two universes?
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 »

Frequently Asked Questions

This FAQ is empty. Add the first question.

User Reviews

Yeah, I don't get it either
16 November 2007 | by (United States) – See all my reviews

I never understood this episode. It's not interesting, nothing happens in it. During those moments when the world is spinning around, I have to laugh because they look like those old "newspapers spinning towards the camera" shots showing a series of headlines, e.g. "Boy Trapped in Refrigerator Eats Own Foot".

Lazarus keeps falling off of cliffs all of the time. The man easily travels through Time and Space and yet he keeps falling into Space all of the Time? When TOS was originally issued on VHS, this was one episode I made sure I didn't buy. There might be more to see in this episode, I just don't have the patience to wade through all of the boredom.

19 of 26 people found this review helpful.  Was this review helpful to you?

Message Boards

Recent Posts
Who will be the last one standing? P_Fenton_Cosgrove
Weak Sets powersroc
captain sulu sea_dog-1
Name Guest Stars Who Appeared Together In Other Projects powersroc
Why 2 different uniforms for Kirk? dcornibe
JJ Abrams reboot sea_dog-1
Discuss The Alternative Factor (1967) on the IMDb message boards »

Contribute to This Page

Create a character page for: