Vak Somoril, a Human of male gender, held the rank of colonel within the ranks of the Imperial Security Bureau. He was stationed aboard the Imperial-class Star Destroyer known as the Reprisal starting in 0.5 ABY. While serving on the vessel, Imperial stormtroopers murdered Major Drelfin of the ISB after Drelfin challenged them for their refusal to eliminate civilians on the planet Teardrop.
Somoril began his own investigation to locate the stormtroopers, but became concerned when Mara Jade, an Emperor's Hand, requested assistance from the Reprisal. Incorrectly believing she was pursuing the deserters and fearing he would be blamed, Somoril tried to mislead her, unaware that her objective was unrelated to the deserters. Somoril, working alongside Kendal Ozzel, the captain of the Reprisal, later tasked two ISB stormtroopers with aiding Jade in her covert operation infiltrating a pirate organization. It was only afterward that he understood her mission was not connected to his concerns.