He first expressed his wish to defect shortly after the Battle of Hoth. His first communiqué with Alliance forces was to the MC80 cruiser Liberty, via an Imperial Communications relay Comm Center. Zaletta's transmission was brief and anonymous, only lasting long enough to give the Rebels a set of coordinates and scant details on an Imperial convoy, which Zaletta said would be "of interest to the Alliance".
The convoy, made up of Sentinel-class landing craft, turned out to contain Bothan slaves on their way to an Imperial Penal Colony. A flight of Rebel Y-wings disabled the ships containing the slaves, which were boarded by a group of Gamma-class ATR-6 assault transports from Tango Group. Not only had the Alliance rescued key allies of the Rebellion, an act which would strengthen the bond between the proud race and the revolutionary group, but they had proved the "anonymous informant's" information to be correct.
The Communications relay Comm Center which Zaletta used to aid the Alliance before his defection
Zaletta, remaining cautious, sent out another secretive transmission, wishing again to prove his integrity. This time, he gave the Alliance information on the secret Imperial research facility deep in the Kuat system. The station was owned and operated by Kuat Drive Yards itself, and seemed to be a test facility for a new experimental reactor system. Taking advantage of the facility's lack of defense, a flight of X-wings launched from the Liberty to investigate. Among their ranks was pilot Ace Azzameen, who, when the facility had been inspected and the order given, blasted open a small hatch on the brim trench of the facility, exposing the cavernous reactor system (which was likely connected with the Death Star project). Azzameen then fired on the reactor core itself, destroying the facility. Once again, Zaletta had proven not only his commitment to the Alliance and to his defection, but revealed just how high up the command chain he was.
Though still apprehensive, the Alliance decided to bring Zaletta in. First, though, they had to find him. The events surrounding the defection of Imperial Grand Admiral Zaarin had been a serious shock to the Empire, and any hopes of initiating the defection himself was severely dashed. Zaletta, therefore had to rely on the Alliance to secure his freedom. Fortunately for him, Zaletta's trust was well placed. The Alliance managed to trace the source of the transmissions by downloading the logs from the Communications Array Comm Center via which the communiques were being routed in a daring raid by Alliance A-wings and the Modified Corvette Python.
Armed with this information, the Alliance raided the Imperial Outpost DX-11a in the Eidoloni system on which Zaletta was stationed. Alliance X-wings, led by Ace Azzameen, attacked the platform and forced all onboard officers to flee. By inspecting the escaping shuttles, Ace was able to locate Commander Zaletta aboard AA-23. The Rebels escorted the shuttle to a deep space rendezvous with the Alliance Nebulon-B frigate Redemption. However, as the shuttle docked and the group prepared to retreat back to the Liberty task force, an Imperial detachment arrived, consisting of an Imperial-class Star Destroyer and an Immobilizer 418 cruiser Restrainer. With their exit blocked, and TIE/sa bombers on the way, the Redemption called in the Liberty. Together, the two capital ships and their starfighter complement were able to destroy the Interdictor and retreat, bringing Zaletta over to "the other side of the fence".
The speediness of the Imperial response was cause for great concern regarding the intentions of Commander Zaletta, who was incarcerated on the Redemption. It was then however, that the Liberty's Tactical Officer, Commander Kupalo, chose to return to the Empire, revealing that he had been brainwashed into an Imperial Agent and was the traitor who had sprung the trap on Redemption. Pilots Azzameen and Olin Garn were able to apprehend the traitor, and Commander Zaletta eventually became the Liberty's new Tactical Officer. Immediately, he put his knowledge of secret Imperial projects to use, culminating in the capture of the Imperial computer that contained the Death Star II plans.
In a twisted irony, this discovery would prove fatal for Zaletta, as his endeavor indirectly resulted in the Battle of Endor, where he would appear to have been killed in the Libertys destruction after it was hit by the Death Star's first superlaser blast.
In X-Wing Alliance, Zaletta was voiced by Andre Ware.