Star Trek (1966–1969)
34 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 »


Official Sites:

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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 »


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!
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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 Weird Science: Magnifico Dad (1994) See more »


Theme From Star Trek
Written by Alexander Courage
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User Reviews

Ambitious and interesting idea.... weakly executed
19 May 2007 | by mstomasoSee all my reviews

This episode of TOS suffered from a mediocre script and very average directing. Robert Brown does a fair job of performing the rather maniacal Lazarus -an interesting biblical allusion, but a bit difficult to interpret the meaning given the character. The cinematography and the script impose limitations that inhibit dramatic development.

The Alternative factor is essentially a sci-fi mystery (hence the choice of Gerd Oswald, known for Perry Mason, as the director). It presents a plot with some interesting, though somewhat impossible, roots in theoretical physics. The known universe is, apparently, about to be destroyed by a malevolent humanoid from the universe of antimatter. Lazarus has been chasing this being for years - to exact revenge for the destruction of his world. The Enterprise crew is stymied and confused (as will be most members of the audience), until the identity of the would-be destroyer is revealed.

Basically, the story line could have been interesting given an hour or so more explanation. As it stands, it appears to be strafed with plot-holes and inconsistent characterization. The franchise, however, learned from its mistakes and did better with similar approaches in a few episodes of TNG and DS9.

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