Stormtrooper Colonel TC-1289 originated as one of many stormtroopers created for the Galactic Empire by Zyix K'zzt within a clone vat. He was destined to be a typical, unthinking drone until the Imperial Security Bureau uncovered K'zzt's secret affiliation with the Rebel Alliance. As a final act of rebellion, K'zzt transferred his entire consciousness into a memory unit, which then implanted it into TC-1289, resulting in them sharing the same physical form.
Although TC-1289 didn't appear to acknowledge his dual identity, he seemed to have overridden his original clone programming, leading to his recognition as a fully sentient being. Consequently, the [Rebel Alliance](/article/alliance_to_restore_the_republic/legends], and later the New Republic, held him accountable for his actions, unlike the mass of other stormtroopers who were merely automatons.
Alliance High Command grew concerned when TC-1289 began contacting Rebel operatives using call signs and signals exclusive to Zyix K'xxt. His mannerisms and speech also deviated from those of standard stormtroopers, raising suspicions about his true nature. Furthermore, a captured operative testified that TC-1289 possessed a rational mind behind his mask, describing him as having "Someone with a split personality... One minute, a bootlicking toady; the other, an intellectual, charismatic gentleman."
Rebel operatives subsequently discovered K'zzt's logs. While their scientists debated the specific details, they generally agreed that he seemed to have transferred his mind, including memories and skills, into the unprogrammed clone before ending his own life. This led High Command to fear that, without his capture, Imperial security might become suspicious of K'zzt's death and, upon learning of an unusual stormtrooper colonel, reopen the investigation and uncover the truth. While the 10,000 credit bounty placed on TC-1289 didn't explicitly state their belief that K'zzt was alive within him, other Rebel operatives were informed of this suspicion.
Despite the bounty, TC-1289 remained in Imperial service during Grand Admiral Thrawn's campaign against the New Republic. His last known whereabouts at that time were aboard the Star Destroyer Crusader within the Kala sector.