Star Trek (1966–1969)
36 user 8 critic

The Alternative Factor 

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.


Gerd Oswald


Don Ingalls, Gene Roddenberry (created by)

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Episode complete credited cast:
William Shatner ... Capt. Kirk
Leonard Nimoy ... Mr. Spock
Robert Brown ... Lazarus
DeForest Kelley ... Dr. McCoy
Janet MacLachlan ... Lt. Charlene Masters
Nichelle Nichols ... Uhura
Richard Derr ... Barstow
Arch Whiting ... Assistant Engineer
Christian Patrick Christian Patrick ... Transporter Chief
Eddie Paskey ... Lesley


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


TV-PG | See all certifications »


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Release Date:

30 March 1967 (USA) See more »

Company Credits

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Technical Specs


Sound Mix:




Aspect Ratio:

1.33 : 1
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Did You Know?


Lazarus manipulates several components in a "high voltage" access tray in order to create an overload, and eventually steal several dilithium crystals. These objects are simply dual banana plugs often used by electronics technicians. See more »


Even after Spock has proved Lazarus to have lied, Kirk allows Lazarus to roam unguarded aboard the ship. See more »


Lazarus: Is something wrong?
Capt. Kirk: No. I have a ship's physician with a strange sense of humor.
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Crazy Credits

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

Alternate Versions

Special Enhanced version Digitally Remastered with new exterior shots and remade opening theme song See more »


Referenced in The X-Files: Fight Club (2000) See more »


Theme From Star Trek
Written by Alexander Courage
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User Reviews

Weird Goatee Beard Changes - Thicker Then Thinner
26 February 2007 | by ErasmicLatherSee all my reviews

I love these old STAR TREK episodes but this must be one of the lamest ever. I couldn't figure out what on earth was going on - nor could Kirk and Spock by the sound of them. Spock keeps making strange and frankly incomprehensible statements like "it's possible...very possible." It's either possible or not, make up your mind, Mr Spock.

Meanwhile, a man falls off a cliff, again and again, and is cured by a small plaster, though blood drips from his mouth. The best parts are Kirk's line "I want facts, not poetry!" and the Enterprise crew hanging out in the recreation room smirking at the state of the canteen coffee while the goatee man prowls about looking ragged. Couldn't Bones have loaned him a spare suit at least?

It's still all splendid fun, of course, and I recommend it wholeheartedly over all modern TV programmes.

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