- "It must be stopped before the contagion spreads. Since neither Empire or Republic can single-handedly destroy this menace with the resources available right now, you must work together to see it done."
- ―Dao Stryver
Independent Operation Sebaddon was a conflict that took place at the end of the Cold War. Initially both the Galactic Republic and the Sith Empire intended to annex the remote planet Sebaddon, but both fleets were ravaged unexpectedly by the amnioid Fastbreeders which forced the ancient enemies to fight together in order to destroy the droids before the contagion spread across the galaxy. The conflict left the resource-rich world unaligned and in a degrading orbit.
In Wild Space smuggler Jet Nebula in the Auriga Fire interdicted the Cinzia which self-destructed shortly after he announced his intention to steal its contents. Although it may not have appeared valuable he did salvage the Cinzia's nav computer and returned it to Hutt matriarch Tassaa Bareesh who announced her intention to auction it to the highest bidder.
Sith apprentice Eldon Ax returned to her Master, Darth Chratis, to report not only her failed mission but the humiliation of being defeated and interrogated by the Mandalorian Dao Stryver. The furious Chratis spared his apprentice only because of his interest in what was asked in the Mandalorian's interrogation, information about Ax's mother Lema Xandret and the location of the Cinzia. Darth Chartis informed his apprentice that Lema Xandret was her mother who had refused to hand her daughter over to the Sith for training and as a result she absconded and successfully went into hiding beyond the reaches of the Empire.
The Empire and Republic both dispatched diplomatic envoys to the court of Tassaa Bareesh in order to acquire the contents of the Cinzia. As both Eldon Ax and a Jedi Padawan who had arrived under orders from Satele Shan, Shigar Konshi, attempted to break into the vault to steal the Navicomputer and the strange device, they were beset by Dao Stryver. During their three-way engagement, the door to the vault melted open and several advanced hexagonal droids marched out, having been produced in the device the Cinzia was carrying. After a lengthy battle with four of the droids, the Navicomputer was captured by Dao Stryver, while Eldon Ax deduced that the droids were trying to escape to their point of origin and therefore must have its coordinates stored in their memory banks. Eldon returned to the Keizar-Volvec bulk cruiser Paramount where she had a droid technician extract the coordinates. Meanwhile, Shigar Konshi used his psychometric abilities to discern the location from a fragment of the artifact. As a result, all three parties proceeded to the world of Sebaddon, which orbited a black hole far above the galactic plane, in the mid rim.
The freighter Auriga Fire was the first to arrive, quickly followed by a battlegroup of fifteen republic ships. However, in order to approach the planet, ships entering the system were required to slingshot around its central black hole, and one of the republic warships was lost when it failed to perform the maneuver correctly. After attempting to negotiate with the inhabitants of Sebaddon through Cinzia Xandret, a clone whom they believed to be Lema Xandret, large heat sources appeared on the surface which Larin Moxla initially thought to be volcanoes, but were in fact the launch sites of multiple ground-to-space missiles.
The inhabitants launched eight ground-to-space missiles against the republic, four of which were destroyed by defensive fire, and another three by the Republic's starfighter screen. One missile managed to strike ventral side of the Corellia just before its engines, embedding itself in the ship. The debris from the other missiles was quickly revealed to be Fastbreeder battle droids, which began boarding the Republic ships. After Jet Nebula sent out an alarm to the Republic fleet, the droids quickly gained control of the Corellia as the Imperial navy arrived. The ships took a great deal of time to reach the battle due to their chosen course of heading straight to the planet rather than slingshotting around the black hole. As they observed the battle, one small Republic cruiser rammed itself into another warship, having been commandeered by the Fastbreeders. The Empire proceeded to launch their fighters once out of the Black Hole's influence, and engaged the Republic navy. After destroying one small ship, Eldon Ax quickly realized their mistake when they entered the cloud of Fastbreeders, and ordered the fighters to be recalled. However, Chratis and Colonel Kalisch ignored her recommendations and ordered the battle to continue. At that moment four additional missiles launched from the surface and the commandeered Republic ships turned to ram the Imperial navy. The fighters took to strafing dense concentrations of the Fastbreeders while the Imperial warships continued on their course. The large missiles separated into sixteen smaller missiles, eleven of which were destroyed by the defensive fire. Five missiles struck the imperial fleet, damaging four large support vessels escorting the Paramount. In retaliation the Paramount launched retaliatory strikes on the missile launch sites, while the fighters attempted to intercept and destroy the drive systems of the commandeered Republic warships. The Paramount heeded Eldon's warning and moved out of the Imperial formation as Sebaddon launched two additional missiles and the first Imperial ship exploded, spreading the droids throughout the rest of the fleet. Multiple Imperial ships then proceeded to copy the Republic's tactic, and separate their uninfected vessels from the commandeered ships.
Meanwhile Captain Pipalidi had taken control of the Republic fleet aboard the Commenor as the Auriga Fire cleared out Fastbreeders and and directed escape pods from the Corellia to the uninfected portion of the fleet. Three more missiles were launched from the surface, which the Republic initially believed to be aimed at no particular target. The Auriga Fire attempted to deal with the Fastbreeders' adaptive tactics by flooding agglomerations of them with energy from its drive systems, which destroyed them as they attempted to absorb it. The Auriga Fire then proceeded to rescue Grandmaster Satele Shan from the wreckage of the Corellia. After her rescue Dao Stryver's ship emerged from a crater on Sebaddon's moon and contacted both the Auriga Fire and the Paramount. The two parties proceeded to meet with the Mandalorian.
After meeting with Dao Stryver, in which he explained to both parties that the Fastbreeder droids would be able to consume the entire galaxy within approximately one generation, the Empire with some help from Ula Vii, an imperial informer masquerading as the Republic envoy, agreed to briefly ally with the Republic to neutralize the threat. Two strike forces were assembled to destroy the central foundry and the central intelligence operations centers, located at the south pole and the equator, while the combined fleet bombarded secondary sites from orbit. Ula Vii was chosen to be the commander of the operation by both parties and stationed aboard the Auriga Fire, where he would act as a neutral interest.
The invasion began with a combined attack run by Republic and Imperial forces on the Fastbreeder droids in orbit, and four thousand troops were committed to the ground assault, while two thousand remained in orbit. Four squadrons of XA-8 and Mk. VI Starfighters punctured holes in the orbital cluster of Fastbreeders which allowed the NR2 Gully Jumper and VT-22 shuttles to pass through. Six missiles were launched in response in order to close the gaps in the orbital defenses, while the Republic and Imperial fleets proceeded to begin long distance bombardment of secondary targets. The dropships deployed their forces from orbit where they would be able to parachute in, unable to be distinguished from debris by the droids. At the same time, Stryver, Nebula, and Vii attempted to triangulate the source of the Fastbreeders' subspace communications.
While a downed VT-22 shuttle struck the equatorial target, Vii, Nebula, and Stryver were able to locate and order bombardment on three subspace communications hubs on the planet's surface, temporarily inhibiting communications. However, during another wave a missile launches, the orbital crowd of fastbreeders opened up at the south pole, allowing Stryver's ship alongside a massive skyhook to emerge from the planet. Likewise, another vessel was produced at the equatorial strike site, which was the central intelligence for the fastbreeders, while the drives were produced on the moon, all three parts moving to conjoin with each other into a single vessel. Although Republic and Imperial vessels had again begun to exchange fire with each other as the alliance broke down, Jet Nebula's droid Clunker had managed to infiltrate the Republic and Imperial networks and take control of their vessels, using them to target the weak points on the skyhook with the Paramount which had been identified by Larin Moxla. However, both the central intelligence ship and skyhook had protected themselves with electromirror shields.
Meanwhile, Satele and Eldon aboard the central intelligence component discovered that the droids were controlled by a clone of Eldon Ax under her original moniker of Cinzia Xandret, along with the remains of the consciousness of Lema Xandret. However, during their conversation the liquified consciousness of Lema attempted to suffocate Cinzia, prompting Eldon and Satele to break the tank, killing Cinzia. Ax was able to then take control of the droids due to her genetic similarity, and used the override codes to shut them down. The old imperial vessel then emerged from the lake, and Ax and Satele emerged from the ship. Ax then turned against her master Darth Chratis and killed him using the Fastbreeders under her control. The droids then drilled down into the planet's mantle, which destroyed all of the fastbreeder technology.
After the battle, Tassaa Bareesh's forces under Sagrillo arrived to claim control of the planet, but were soon outmatched by the arrival of both Republic and Imperial reinforcements. Jet Nebula had erased all history of the operation, and Dao Stryver disappeared. Lieutenant Moxla was permanently promoted to that position and given command of a new special forces division including Ses Jopp. Captain Pipalidi was also promoted to Colonel for her actions during and after the engagement. Republic forces attempted to salvage rare metals from the world but Imperial forces limited their access. A report to Supreme Commander Stantorrs stated that evidence of the Fastbreeder technology had been destroyed, and the planet's orbit had been disturbed and it was in a degrading orbit towards the system's central black hole.
- The Old Republic: Fatal Alliance (First appearance)