During the time of the Clone Wars, the Confederacy of Independent Systems captured Even Piell, a Jedi Master, along with the entire crew of his Star Destroyer. Piell's forces were ambushed by the Confederacy navy while en route from the Outer Rim Territories, and after this attack, it was revealed that Piell had knowledge of the coordinates for the crucial Nexus Route.
The Separatists took Piell, Wilhuff Tarkin (a Captain in the Republic Navy), and their clone trooper soldiers into custody when Separatist battle droids boarded their severely damaged cruiser, as they aimed to steal Piell's knowledge of the Nexus Route. To prevent this intelligence from being obtained by the enemy, the Jedi Order initiated a mission to liberate Piell from his imprisonment within the heavily fortified Citadel prison, hoping to rescue him before the Separatists could successfully extract this critical information.