While on a mission to liberate the planet of Christophsis from a Separatist siege, clone Marshal Commander Cody and clone trooper Captain Rex begin to suspect a traitor amongst their clone army. Cody and Rex begin to suspect this after a series of events takes place in a co-op mission with Jedi knights Anakin and Obi-Wan, leaving the commander, the captain and the Jedi to find out who the traitor is.