Years prior to the Battle of Yavin in 0 BBY, Lando Calrissian and L3-37 were ambushed in the Halthor sector by an Imperial interdictor as they delivered a shipment of All Terrain Defense Turret walkers. The ambush resulted in Calrissian and L3 losing the entirety of the cargo.
After the Battle for Tatooine, Tatooine rebel cell of the Rebel Alliance came in possession of Calrissian's holojournals, including , and received chatter from the criminal underworld of the older and heavily-armed AT-DT walkers being utilized. Saponza deduced that someone must have found Calrissian's shipment, and that people would be hunting for the rest of the cargo. Saponza and his partner embarked on a .