Following the establishment of the Galactic Empire, a Separatist holdout persisted on the planet Desix. This group was under the leadership of Governor Tawni Ames, with a T-series tactical droid serving as her second-in-command. The Separatist holdout's existence concluded with the mission to Desix. Sometime between 19 BBY and 18 BBY, the Empire replaced Ames with Governor Grotton. The holdout, refusing to acknowledge Imperial authority, took the newly appointed governor and his TK trooper squad hostage, which ultimately triggered the events leading to the holdout's demise.
The majority of the military force of the holdout was composed of droid units originating from the former Confederacy of Independent Systems. This included a droid battalion featuring at least twenty B1-series battle droids, multiple BX-series droid commandos, several droidekas, an air strike team, an OOM command battle droid, and an Armored Assault Tank Mk I. These droids were reprogrammed with the objective of defending Desix against an Imperial invasion. Command of these forces rested with a T-series tactical droid, who reported directly to Governor Tawni Ames.
During the operation on Desix, these forces were strategically positioned. One squad was assigned to protect the outskirts of Desix City at a bridge. An air strike team was stationed at the city walls. Several squads patrolled within the city itself. Finally, a squad consisting exclusively of commando droids was located inside the bell tower, where Ames and the T-series tactical droid were also situated.
When an Imperial Nu-class attack/transport shuttle entered the planet's atmosphere, Ames instructed the Tactical Droid to initiate an attack on the incoming vessel. The Tactical Droid followed through, directing the repurposed Separatist Tank and the Air Strike Team to target the shuttle. This resulted in the shuttle crashing in Sector Five within the farmlands. Following the crash, Ames then commanded the Tactical Droid to dispatch reconnaissance units to the crash site to determine if there were any survivors.
A scouting party, consisting of five B1 battle droids, was dispatched to the wreckage. Finding no survivors, they relayed this information back to the Tactical Droid. The Tactical Droid then instructed the B1 Battle Droids to return to the fortified city. However, just as the battle droids were preparing to depart, the remaining members of Crosshair and Cody's team launched an assault on the B1 Battle Droids, creating a window of opportunity for the squad.
The squad then navigated the terrain and reached a bridge that connected a city to the Farmlands. As the squad deliberated on how to gain entry to the city, CT-9904 proposed a plan: he would draw the tank's fire, allowing the remainder of the squad to advance toward the Main Gate. Cody, after some hesitation, agreed. Crosshair intentionally missed his shots at the droids operating a tank using his 773 Firepuncher rifle. This prompted the tank to reposition itself toward Crosshair's location, enabling him to fire at the tank's barrel, causing it to explode. With the tank neutralized, Cody and his men advanced toward the main gate while Crosshair provided covering fire. With the droid air strike team dealt with, Cody and some clone troopers rappelled to the top of the main gate and opened the gate allowing the rest of Cody's squad including Crosshair to enter the city.
Upon entering the city, Cody divided his forces, assigning team two to the southern sector, while Cody, Crosshair, Nova, and Wyler took the northern sector. This prompted the tactical droid to issue Protocol 4 to his forces.
After engaging in intense close-quarters combat within the city, during which Wyler was killed by the droids, the northern team successfully reached the city square and infiltrated the Bell Tower. Inside, the troopers were ambushed by commando droids, resulting in Nova's death. To escape the ambush, Crosshair and Cody were pinned down by the commando droids at the staircase of the Bell Tower however managed to defeat many of the commando droids. During this battle, Crosshair sustained an injury but assured Cody that he could still make the shot. Trusting Crosshair, Cody threw a puck as far as he could toward the tactical droid, allowing Cody to kill two commando droids and the tactical droid in one shot.
Upon reaching the upper level of the Bell Tower, they found Governor Tawni Ames holding Governor Grotton at gunpoint. However, after some convincing, Ames released Grotton. Immediately upon being freed, Grotton ordered Cody to kill her. Cody, having promised Ames a peaceful resolution between her people and the Empire before Grotton's order, found himself unable to comply. Consequently, Crosshair took it upon himself to kill her instead. Following Ames' death, Grotton instructed the two clones to display her body in the city square.
Ames' death marked the end of the Desix Separatist holdout and the beginning of the Imperial occupation of the planet. Distraught by the events that had unfolded, Cody departed with Crosshair and a small contingent of clone troopers aboard a shuttle bound for the planet Coruscant, where he subsequently deserted.