A powerful artificially intelligent Earth probe, with a murderously twisted imperative, comes aboard the Enterprise and confuses Capt. Kirk as his creator.



(created by),

Watch Now

$0.00 (SD) with Prime Video





Episode complete credited cast:
Makee K. Blaisdell ...
Singh (as Blaisdel Makee)
Barbara Gates ...
Meade Martin ...
Arnold Lessing ...
Security Guard
Vic Perrin ...
Nomad's Voice (voice)


The Enterprise encounters a powerful energy force that has apparently killed all human life in a solar system with over one billion inhabitants. They identify the culprit as a small space probe that had its origins on Earth. Called Nomad, it merged with another and, as a result, took on a new mission to destroy all biological beings as being imperfect. It believes Captain Kirk to be its creator and, as such, has spared the Enterprise and its crew, at least temporarily. Written by garykmcd

Plot Summary | Plot Synopsis


See all certifications »


Official Sites:



Release Date:

29 September 1967 (USA)  »

Company Credits

Show detailed on  »

Technical Specs


Sound Mix:


Aspect Ratio:

1.33 : 1
See  »

Did You Know?


The story implied that Nomad was Earth's first probe out of our solar system. In actual fact, Pioneer 10 was the first craft to reach interstellar space. See more »


Spock states that the Enterprises' shields absorbed the equivalent of 90 photon torpedoes worth of energy. Yet when Nomad absorbs 1 photon torpedo of energy, Kirk acts genuinely astonished and asks if Spock's sensor equipment is damaged. Why would he be that amazed, if his ship just absorbed 90x that amount of energy? See more »


Spock: [Places hands on Nomad and conducts mind meld] I am Nomad. I am performing my function. Deep, emptiness. It approaches, collision, damage, blackness. I am the other. I am Tan Ru. Tan Ru. Nomad. Tan Ru. Error. Flaw. Imperfection. Must sterilize. Rebirth. We are complete. Much power. Gan Ta Nu Ika. Tan Ru. The creator instructs, search out, identify, sterilize imperfections. We are Nomad. We are Nomad. We are complete. We are instructed. Our purpose is clear. Sterilize imperfections. Sterilize ...
See more »


Referenced in Star Trek: The Motion Picture (1979) See more »

Frequently Asked Questions

This FAQ is empty. Add the first question.

User Reviews

Nomad's Goal: Sterilize All Biological Units
14 August 2006 | by (United States) – See all my reviews

Yipes, Kirk's taken aboard some problematic entities before, but nothing quite so dangerous as this invincible little machine whose only goal is eradicating human beings. Well, Kirk had no choice really - the first act depicted the Enterprise as just one more power blast away from being vaporized. But, boy, that Kirk is one lucky starship captain (when you think about it, plain luck plays a huge role in Kirk's incredible Starfleet career) - his name happens to resemble that of Nomad's creator; that is, the creator of the original Nomad. The new upgraded version here has the power to wipe out the populations of entire solar systems - a benefit of having joined with some other alien probe. This kind of act - one of sheer genocide - should be almost unimaginably horrific, but is sort of brushed over in this episode, perhaps the main weakness in the storytelling. Sure, McCoy acts as indignant as he can be, but he reacts more intensely over what happens to Scotty & Uhura here. Scotty seems to have perfected the hot-tempered, impulsive crewman in this and the previous episode, "Who Mourns For Adonais?" In that last one, he was walloped by the alien Apollo; in this, he's killed by the alienated machine - yes, this is Scotty's final episode...just kidding.

Probably the strongest aspect of this episode is how they were able to create and convey an interesting character out of what amounts to a hovering metallic cylinder. Somehow, with the fine writing, the dialog, and the voice of actor Perrin, we get a fully-realized creation, one which inspires both dread and, more impressively, actual sympathy. Think the "Charlie X" character from the first season, done up as a super-robot. This Nomad, an early version of actual robotic life - an alternate sort of life - believes it has found its mother, Kirk. Like any child eager to please, its actions now revolve around trying to impress his mother/creator. It's kind of a touching turn of events and, when disillusionment sets in - when it realizes Kirk is just another biological unit - it becomes hurt & pouting, refusing to speak, until it at last says 'stop,' clearly in a tone suggesting profound sadness. Adding to the overall tragedy, 4 red-shirts are obliterated in short order - Nomad doesn't mess around. It's all the more embarrassing that this episode concludes with one those cutesy exchanges between the main trio - hey, guys, what about those billions of dead? Some respect, hm? This episode was essentially remade as "Star Trek-the Motion Picture" in '79, with a somewhat larger budget.

8 of 9 people found this review helpful.  Was this review helpful to you?

Message Boards

Recent Posts
etiquette...again! timmytony80
Wink of an Eye question soulaco2
Mirror, Mirror question soulaco2
Immunity Syndrome sukhisoo
An Alternative Universe of Stories: The Entire Original Series Doctor_Omega
Captain Kirk's Career magolding-94772
Discuss The Changeling (1967) on the IMDb message boards »

Contribute to This Page

Create a character page for: