In 3643 BBY, amidst Darth Angral, the Sith Lord's, revenge campaign targeted at the Galactic Republic due to the death of his son, Tarnis, a conflict erupted within Doctor Nasan Godera's advanced laboratories situated on the planet Taris. A young Jedi Knight launched an assault on the Imperial soldiers occupying the site, aiming to find Godera and safely extract him from Taris. However, a complex scheme orchestrated by Watcher One of Imperial Intelligence enabled the Imperial operative to escape with Godera, while the Knight engaged the remaining Imperials. As Watcher One transported Godera to his base, his agents attempted to deceive the Jedi into believing Godera had perished, but Godera's droid assistant, RE-M0, revealed the truth. With their deception exposed, the Imperials attacked the Jedi Knight, and following the confrontation, Watcher One struck a bargain with the victorious Jedi, securing time to interrogate Godera for his scientific expertise.
During the Cold War between the Sith Empire and the Galactic Republic in 3643 BBY, Darth Angral, a Sith Lord, initiated a personal war against the Republic in response to the death of his son, Tarnis, at the hands of a young Jedi Knight. After seizing control of several Republic superweapons, Angral deployed Watcher One, an operative from Imperial Intelligence, to the planet Taris with the mission of capturing Doctor Nasan Godera, a Republic scientist who had sought refuge there. Upon learning that the same Jedi Knight responsible for Tarnis's death had arrived on the planet seeking Godera, Watcher One was compelled to expedite his efforts. Utilizing equipment located at one of Godera's laboratories, Watcher One traced the doctor's biosignals to another lab situated within the Brell Sediment region. Subsequently, Watcher One destroyed the facility's computer to prevent the Knight from accessing it and left behind a detachment of Imperial soldiers before departing for the Brell Sediment to capture Godera.

A group of soldiers under Watcher One's command stormed the laboratory in the Brell Sediment, securing it, and they took Godera captive in the facility's main chamber after rendering him unconscious. Simultaneously, the Jedi—aided by Godera's droid assistant, RE-M0—repaired the first lab's computer and tracking relays, enabling the Knight and a companion to pinpoint Godera's location at the Brell Sediment lab. As Watcher One prepared to extract the scientist and return to his base, he was alerted to the impending arrival of the Jedi, prompting him to set a trap: an Imperial Shadow Captain, utilizing a holoprojector to impersonate Watcher One, along with a squad of stealth Shadow Commandos, awaited in the main lab with a corpse disguised as Godera. Captain Gerrard's forces secured the rest of the facility while Watcher One used a holoprojector to disguise himself as a Rodian.
Watcher One, accompanied by an unconscious Godera, encountered the Knight at the facility's entrance, where the operative—posing as "Kulaa"—asserted that he and the other man were Godera's assistants. Claiming that his fellow assistant had been injured during the Imperial assault on the facility, Watcher One misled the Knight into allowing him to leave with the unconscious scientist. Meanwhile, the Knight and a companion ventured deeper into the facility, battling through the Imperial soldiers within to reach the main chamber. However, the Knight was dismayed to discover "Doctor Godera" lying dead at the feet of two Imperial commandos and "Watcher One," who claimed that the scientist had taken his own life rather than face interrogation.
"Watcher One" proposed a truce and promised to depart Taris, but his conversation with the Knight was interrupted by the arrival of RE-M0. The droid had performed a second trace on Godera's location shortly after the Knight had departed for the Brell Sediment lab, confirming that Godera was still alive and elsewhere. With the deception exposed, the Shadow Captain cursed and shot RE-M0 with his blaster pistol before deactivating the holoprojector, and his commandos opened fire on the Knight. In the ensuing conflict, the Jedi and the Knight's companion emerged victorious, and Watcher One—who had reached his base in the ruins of an old transport station—contacted the Jedi via the facility's communications terminal.

After explaining the deception, the operative preempted any response from the Knight by informing the Jedi of a more urgent threat: a Sith assassin was en route to eliminate a nearby Republic colony. In exchange for time to interrogate the scientist, Watcher One provided the Knight with the location of the colony, enabling the Jedi to stop the assassin from killing the colonists. Subsequently, the Knight tracked down Watcher One and rescued Godera, but the operative had already interrogated the scientist about his knowledge of superweapon technology and transmitted his intelligence to Darth Angral.
The battle in the Brell Sediment facility was first depicted in the Jedi Knight-class mission "Catching Up With Watcher One" in Star Wars: The Old Republic, a video game developed by BioWare and released in 2011. The mission concludes with Watcher One offering a deal for time with the player, contingent on the player's alignment. Players aligned with the light-side are informed about the assassin, while those aligned with the dark-side are informed about a deal for Jedi artifacts being negotiated between a Sith and pirates nearby. Players can also reject Watcher One's offer for opposite alignment points, but since the Jedi Knight is typically a light-side player, it is assumed that the Knight rescued the colonists.