In the year 19 BBY, a space battle erupted within the Atoan system, situated in the Ghost Nebula. This conflict involved the forces of the Galactic Empire, commanded by Darth Vader, and the Atoan defenders.
During his quest to locate the missing Garoche Tarkin within the Ghost Nebula, Darth Vader interrogated Lady Saro, an Atoan sorceror who had been captured. Vader sought information regarding the admiral's location. Saro stated that, if her conditions were satisfied, she would guide the Imperial forces to the remnants of the Star Destroyer that Tarkin had previously commanded.
Spurred by this information, Vader departed from his own Destroyer aboard his black interceptor, accompanied by an escort squadron of V-wings and his subordinates Voca and Shale, with the intention of examining the wreckage for any available clues.
However, the Imperial fighters only managed to find evidence of sabotage on the Destroyer before they faced an assault from Atoan starfighters. Despite the Atoans achieving some initial victories, Vader quickly reorganized his squadron, and the Imperial pilots managed to hold their ground. They realized that speed and agility were crucial advantages, qualities that the Atoan ships lacked.
Following this shift in momentum, Vader instructed his wingmates to disperse, and he relentlessly pursued the remaining solitary Atoan ship, ultimately forcing it to crash-land inside a hangar located on the damaged Destroyer. Vader eliminated one of the pilots, but kept the other alive for the purpose of interrogation.
Before Vader executed him, the pilot divulged crucial details: a world covered in tar was to be the next destination in the search for Garoche Tarkin. Vader opted for a stealthy approach, also aware that Emperor Palpatine's directives were for Vader to assassinate Tarkin, in order to incite anger and resolve in Garoche's father.