During the era of the Galactic Civil War, a group of Alliance to Restore the Republic advisors, working alongside the indigenous Sessehshellah, carried out a sabotage operation targeting an Imperial hydrocarbon refinery located on the planet Shaymore. After the sabotaging of an Imperial power station on the same world and the acquisition of a comm unit scrambler, the Alliance and their Sessehshellah allies discovered that the Shaymore hydrocarbon operation was under pressure to increase its output tenfold within the next year, or face closure. Furthermore, the refinery's reserves represented a substantial portion of the Empire's total supply.
The joint Alliance and Sessehshellah team used a raft to approach the refinery, enabling team members disguised as Imperial soldiers to rush across the boat dock and successfully deceive the guards. Simultaneously, the Sessehshellah members submerged themselves in the drainage ditches, where they strategically placed explosive charges on the storage tanks' drainage valves. As the battle unfolded, the Alliance operatives found themselves seemingly isolated, only to be rescued by a large contingent of Sessehshellah warriors who stormed the compound and engaged the Imperial forces.
The allied forces of the Alliance and Sessehshellah fought their way to the boat dock, where they seized control of a cruiser. As they rapidly departed the facility, the demolition charges detonated, resulting in a massive explosion. Imperial forces pursued them in armored landspeeders, which forced the Alliance and Sessehshellah to abandon their captured vessel in the surrounding marshes. The Imperials then summoned reinforcements, who arrived in a landcruiser, only to be ambushed by the Alliance and Sessehshellah forces within the marshy terrain.
With the refinery's destruction, the Empire chose to cease its hydrocarbon operations on the planet, and the commander in charge was recalled in disgrace. In the aftermath of these events, the Sessehshellah people successfully regained control of their homeworld.