The Undervaults of Gwongdeen, situated on the planet Gwongdeen, functioned as a highly guarded storage complex. Within a safety-deposit box located in the Undervaults, Kolac Pru, a Kaminoan researcher, kept a specimen of the thornsuckle plant. Mahjo Reeloo, who previously served as his aide, pledged to eradicate it. To reach the Undervaults, she enlisted the services of Han Solo and Chewbacca, smugglers, transporting her aboard the Millennium Falcon. Their journey included a detour to Dhandu 3, where they pilfered a key to a neighboring deposit box belonging to Jayyar Lu-wehs. Upon arrival at the Undervaults, she positioned a defoliator explosive within Lu-wehs' storage container, only to discover that Pru had already recovered the dangerous plant and intended to clone it for the Mandragonian Mob.