is responding to a distress signal in the Malurian system, where a team of Federation scientists is working, but they can’t get a response. Spock reports the population of four billion is… gone. An unidentified source opens fire on them and they survive the hit, which reduces their shields by 20%. Four more hits will shatter their shields. They finally manage to locate the source of the energy bolts and fire a photon torpedo, but it’s unaffected. The barrage continues and the shields go down, and Kirk sends out a message asking for contact and identifying himself by name. Spock finally identifies the source: a metal cylinder a meter long. The attacker responds with mathematical code, asking for access to their databanks. Kirk agrees and the attacker identifies itself in English as Nomad, saying it’s non-hostile. Kirk agrees to beam it aboard and the small metal cylinder appears in the transporter chamber.
It has a protective screen. I cannot get through.
What do we do, go up and knock?
Relate your point of origin.
They are unable to scan it through its screens and the device asks for their “point of origin.” They determine that the device isn’t a ship, but a computer. It says it has been altered since the “accident,” and Kirk remembers a Nomad probe launched centuries before. It asks to scan their star charts to determine their point of origin and floats along to the auxiliary control room. There it determines they are from Earth and believes Kirk is its creator and says that sterilization against the ship was unnecessary. When asked it explains that its mission is to seek out and “sterilize” imperfect life forms. Kirk balks at being called its “creator” until Spock confirms him as the creator and says Kirk was testing Nomad. Nomad concedes there was much damage in the accident.
This is one of your units, creator?
Yes, he is.
It functions irrationally.
Calling them outside, Spock explains there was an Earth probe named Nomad that was damaged and lost during a meteor storm, and its mission was simply to seek out new life forms. Meanwhile, Uhura is singing on the bridge and Nomad hears her over the comm. unit and goes to investigate. In the briefing room, they bring up the files on Nomad’s creator, Jackson Roykirk, and conclude that Nomad has mistaken Kirk for its creator. The blueprint is similar and they believe it somehow merged with an “Other” that it has mentioned. Realizing it will eventually destroy them, Kirk orders a security team to guard Nomad only to discover it's gone.
It would seem that Nomad is now seeking out perfect life forms, perfection being measured by
its own relentless logic.
If what you say is true, then we've taken aboard our vessel a device which sooner or later must destroy us.
Nomad arranges on the bridge and while Scotty lets Kirk know, the device approaches Nomad and tries to determine what “singing” and “music” means. When she can’t answer, it fires a beam at her and Scotty tries to intervene. Nomad blasts him back, dead. When Kirk arrives, Nomad offers to “repair the unit” and Kirk orders it to do so, giving it the ship’s anatomy tapes. It goes to Sickbay and “repairs” Scotty, bringing him back to life. Kirk orders it to repair Uhura as well, but it’s unable to do so since it wiped her knowledge. McCoy concludes they can re-educate her on their own. Kirk has two security guards escort Nomad to the brig and orders Spock to analyze it.
That unit is defective. Its thinking is chaotic. Absorbing it unsettled me.
That unit is a woman.
A mass of conflicting impulses.
Nomad refuses to lower its shields until Kirk orders it to do so, but Spock needs to enter into a Vulcan mind meld to confirm his hypothesis. Melding, Spock confirms that Nomad merged with another probe, Tan Ru. Kirk is forced to break the contact and get Spock outside, where the first officer reveals that Nomad was damaged in deep space and met another alien probe, Tan Ru. Tan Ru’s objective was to sterilize soil samples as a prelude to colonization. The two merged and became one, and now the single unit has determined to seek out and sterilize imperfect life forms. It’s the only fact it believes Kirk is its creator that has spared the crew.
We... are... Nomad. We... are... Nomad. We are complete. We are instructed. Our purpose is clear.
Sterilize imperfections. Sterilize imperfections.
Nomad burns out the brig’s force field and leaves, disintegrating the security guards when they try and interfere. It goes to Engineering and begins making “repairs,” accelerating the ship up toward Warp 15. It only stops when Kirk orders it to. When they confirm the security guards are dead, Kirk gets angry and points out that he’s an imperfect biological unit. Nomad is forced to consider the inconsistency and returns to the brig under guard to calculate the problem before it returns to “launch point.” As it leaves, they realize it plans to return to Earth… where it will destroy all imperfect life forms there that it finds.
I suspect it is about to reevaluate its creator. Captain, it may have been unwise to admit to Nomad that you are a biological unit. In Nomad's eyes, you must now undoubtedly appear imperfect.
Nomad disintegrates the two new guards then goes to Sickbay and scans Kirk’s personnel and medical history files. Having determined Kirk is an imperfect biological unit, it goes to Engineering and knocks out the crew, then starts shutting down life support. Kirk orders Scotty to take anti-gravs to Engineering then goes to confront Nomad. It refuses to obey Kirk’s orders and insists that it’s perfect. It’s unable to compute how an imperfect biological unit created it, and Kirk pushes the point that Nomad considers him its creator. When it agrees it must destroy anything imperfect, Kirk points out that it made an error in identifying Kirk as its creator, and subsequent errors in not catching the initial mistake or sterilizing itself. Nomad is unable to resolve the error, and Kirk and Spock attach the anti-gravs and get it to the transporter room. Kirk orders it to carry out its programming and they beam it out into space where it self-destructs, sterilizing itself.
you are imperfect!
Exercise your prime function!
Later on the bridge, McCoy reports that Uhura is recovering and Spock notes that he is impressed by Kirk’s use of logic, and regrets the waste of destroying Nomad. Kirk can only joke, noting he’s lost his “son” the doctor.
You saw what it did for Scotty. What a doctor it would've made. My son the doctor. Kind of
gets you right there, doesn't it?