Both humans and Klingons have been lured to a planet by a formless entity that feeds on hatred and has set about to fashion them into a permanent food supply for itself.


(as Marvin Chomsky)


(created by),

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Episode complete credited cast:
Lt. Johnson (as David Ross)
Mark Tobin ...


Having found a Federation colony of 100 people completely destroyed, Kirk and the Enterprise have to deal with a nearby Klingon vessel which they believe must be responsible for the colony's destruction. When the Klingon ship is disabled, they, in turn, assume they were attacked by the Enterprise. There is obvious tension between the Enterprise crew and its Klingon enemies. Unbeknown to Kirk and his Klingon counterpart, Kang, this is the work of an alien being that gets its energy from the friction and emotions between sentient beings. The natural animosities between the two parties feed its appetites. When the creature is beamed aboard the Enterprise, it purposely creates tension among the crew, to its benefit. The situation eventually forces Kirk and Kang to work together to defeat it. Written by garykmcd

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Release Date:

1 November 1968 (USA)  »

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Aspect Ratio:

1.33 : 1
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Did You Know?


The Klingon who says, "Stand and fight, you cowards!" is Pete Kellett, who previously appeared in "Mirror, Mirror" as Farrell, Kirk's henchman. See more »


When a sword appears in Kirk's hand, it is obviously blunted and dulled. It should have been sharp and dangerous for the camera close-up. See more »


Mr. Spock: The cessation of violence appears to have weakened it, Captain. I suggest that good spirits might make an effective weapon.
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Referenced in Free Enterprise (1998) See more »

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User Reviews

A hate parasite
25 May 2014 | by (Buffalo, New York) – See all my reviews

The Organian forced peace may have been obtained in a previous episode, but things are still tense between the Federation and the Klingon Empire. Anything can set it off and in this episode some thing nearly does.

Some of the Star Trek regulars are trapped in a section of the Enterprise that has been sealed off. Futuristic weapons have been taken away and our regulars have been given swords. That puts them at a disadvantage with the warrior society the Klingons have since they prize skill in hand to hand type combat. Still our guys hold their own.

It soon becomes apparent that something is creating this competition and is feeding off the energy of hate that is created by the humans and Klingons. There's an old expression that feuds themselves take on a life of their own and sometimes it's forgotten why they start. This episode gives credence to that idea.

Michael Ansara plays the leader of the Klingons and he's well suited to the part of Kang. Ansara repeated his role in future Star Trek shows. He and William Shatner have to realize there's a common enemy out there.

It's an interesting allegory and can be applied to the state of this world's politics then and now.

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