- For other uses, see Kirk.
Korby had hoped that the creation of the android would impress the original Kirk and serve to convince him to cooperate with his plan to ultimately replace all humanoid life in the galaxy with androids. However, his efforts were unsuccessful and Korby began to employ the android to impersonate Captain Kirk.
While his mind was being scanned by the android duplicator, Kirk was able to program the android to behave in an extremely antagonistic manner towards his first officer Spock by repeating the phrase, "Mind your own business, Mr. Spock! I'm sick of your half-breed interference, do you hear?" While aboard the USS Enterprise, the android used this phrase when Spock inquired as to why he was planning on discussing the ship's destination schedule with Korby. Given that this comment was completely uncharacteristic of Kirk, it served to alert Spock, as the original Kirk had intended, that something was wrong and to investigate. The android told Korby that he "felt quite at home on the Enterprise."
Shortly after his return to Exo III, the android Kirk was vaporized by his fellow android Andrea as he refused her request for a kiss, deeming it to be "illogical." She did so as she believed that he was the original Kirk, whom she had previously kissed on several occasions. Kirk used Andrea's lack of feeling about killing his android duplicate to illustrate to Korby that an android society would be far from a perfect one as the androids would not hesitate to kill each other if they deemed it necessary. (TOS episode: "What Are Little Girls Made Of")
In 2268, a second android duplicate of Aaron Brown returned to Korby's laboratory after being trapped in another cavern for more than a year. After reviewing one of the facility's playback units, Brown learned that Korby, Andrea, the other Brown and Ruk were all dead and that Captain Kirk was responsible. With Korby's death, he took it upon himself to bring about his creator's vision of a perfect society composed entirely of androids and constructed another Kirk android to help him do so. The second Kirk duplicate immediately took command of the operation, telling Brown that he was "only a faint echo of a second-rate scientist" whereas he had all the knowledge, memory and experience of a starship captain.
The Kirk android and Brown were able to lure the USS Hood to Exo III with a distress call in which they claimed to be the last surviving members of Korby's expedition. The android used the pseudonym "Johann Zezel" but the Hood's captain Joaquin Martinez recognized him immediately as he had met the original Kirk on Starbase 5 on one occasion. Martinez and the rest of the landing party were killed and replaced with android duplicates. Using the Hood, the Kirk android had the duplication technology transported to Minos V, where they began to kidnap colonists and replace them with androids.
While aboard the Hood, he learned that the crew of the Enterprise - including the original Kirk - were due to arrive on Tranquility VII for shore leave. He cheated the local Rythrian crime lord at a card game and, as he had planned, Kirk was captured by his men almost immediately after his arrival. The android was therefore able to take his place his place as captain of the Enterprise.
After taking command of the Enterprise, the Kirk android found that he had a strong desire to use the phrase "Mind your own business, Mr. Spock! I'm sick of your half-breed interference, do you hear?" whenever the ship's first officer questioned his actions. It intensified as time passed but he was nevertheless able to resist it.
The original Kirk had recently saved the life of a young T'nufoan man named K'leb and his people's customs demanded that he was bound to serve him for a year. K'leb began to suspect that the android was an imposter.
The Kirk android then ordered the Enterprise to Minos V on the pretext of searching for missing colonists. In the process, the search parties - including Spock, Lieutenant Hikaru Sulu, Ensign Pavel Chekov and Nurse Christine Chapel - were captured and replaced with androids.
The original Kirk was able to escape Tranquility VII and made his way to the Hood. He and a group of the surviving Human officers were able to destroy the androids and retake the ship. After getting a full list of the replaced Enterprise crewmembers from Lieutenant Nyota Uhura, Kirk beamed over to the ship and gathered Montgomery Scott and the rest of the engineering crew to retake the ship. The Kirk android and his followers attempted to escape but Kirk was able to track them to the shuttlebay and trick them into destroying a shuttlecraft. The resulting explosion destroyed the androids.
The Enterprise then returned to Minos V and Kirk rescued the original versions of Spock, Sulu, Chekov, Chapel and his other crewmates. As Brown had refused to kill them, Kirk allowed the surviving androids to settle on Palantine IV, which was unable to support organic life. (TOS novel: Double, Double)