Sarsh was a Force-sensitive individual who served the Navigators' Guild as a Pathfinder navigator. In 18 BBY, the Grysk operative "Jixtus" hired Sarsh and Pathfinder Qilori to navigate the Kilji picket cruiser Hammer and the Kilji war cruiser Anvil, respectively, to the Unknown Regions' Rapacc system. After the starships arrived in the star system, the Chiss heavy cruiser Springhawk destroyed the Anvil, and the Hammer fled to the Unknown Regions' "Sunrise" system.
Qilori, who used an escape pod to escape the Anvils destruction, was rescued by the Springhawks commander, Senior Captain Mitth'raw'nuruodo, core name "Thrawn." Under Thrawn's directive, Qilori used the Force to track down Sarsh, bringing the Paccosh-commandeered Nikardun blockade frigate Aelos to the Sunrise system, where the frigate's crew boarded the Hammer. After Thrawn had Sarsh steal Kilji data, the group left the picket cruiser. Shortly afterward, the Pathfinder brought a Paccian troop transport in and out of hyperspace to know when Jixtus's fleet would arrive at the system.
A Force-sensitive individual, Sarsh was recruited by the Pathfinders, a group of navigators that served the Navigators' Guild. When he was recruited, he met the fellow Pathfinder Qilori before they were sent to their respective starships. In 18 BBY, the Grysk operative known as "Jixtus" hired Sarsh and Qilori to navigate two of the Kilji Illumine nation's cruisers, the Kilji picket cruiser Hammer and the Kilji war cruiser Anvil, the two cruisers of Illumine General Crofyp's task force. Sarsh and Qilori navigated the Hammer and the Anvil, respectively, bringing the Kilji warships to the Unknown Regions' Rapacc system.
Subsequently, the Kilji force fought against the Chiss heavy cruiser Springhawk and the Paccosh-commandeered Nikardun blockade frigate Aelos. Qilori's cruiser was destroyed; however, he was able to escape with an escape pod while the Hammer fled to an Unknown Regions system known as the "Sunrise" system. The Springhawks commander, the Chiss Senior Captain Mitth'raw'nuruodo, core name "Thrawn," rescued Qilori and tasked him with using the Force to track down Sarsh.
Senior Captain Mitth'raw'nuruodo (pictured) spoke with Sarsh aboard the Hammer.
The Hammer arrived in the Sunrise system shortly afterward, keeping station with one of Jixtus's warships. The Aelos arrived shortly afterward, and the blockade frigate's crew—consisting of Thrawn, Qilori, and a squad of Paccian commandos—boarded the picket cruiser. The commandos quickly eliminated every Kilji aboard and let Sarsh, who was on the Hammers bridge, live. Thrawn spoke with Sarsh in the Taarja trade language, tasking him with collecting data on the Illumine's battle fleet, the Illumine Kilhorde.
The senior captain's request startled the Pathfinder, who refused, as the Navigators' Guild forbade collecting a ship's data; however, he accepted after the Chiss commented that he might not be worth taking along, giving the Chiss a Kilji data rectangle with the data he requested. As the boarders left for the Aelos, Thrawn instructed Qilori to keep his fellow Pathfinder quiet and moving. After Jixtus's warship escaped, the group stayed in a mining compound on a planet known as "Sunrise," which was located in the eponymous system.
Shortly afterward, Qilori left the planet and reported to Jixtus, who asked him to tell him how Sarsh had survived the Hammers destruction the next time they spoke. While Jixtus's fleet traveled to the Sunrise system, Sarsh stayed aboard a Paccian troop transport in the outer system, bringing the troop transport in and out of hyperspace so that Thrawn knew when the Grysk fleet arrived. After the Grysk force was destroyed by a Chiss fleet under the Thrawn's command, the senior captain told Qilori, who thought Sarsh had died, to return his fellow Pathfinder to the Navigators' Guild Concourse 447 space station.
Sarsh was not Qilori's friend, and he spoke in a quavering voice while his winglets shook during his conversation with Thrawn.
Sarsh appeared in the 2021 novel Thrawn Ascendancy: Lesser Evil, the final installment of Timothy Zahn's Star Wars: The Ascendancy Trilogy.