After groundquakes have devastated the planet Aleen, a Republic relief effort arrives, including the droids R2-D2 and C-3PO. When the native Aleena's pleas go unheard, it becomes the duty of the droids to embark on a surreal journey through Aleen's subterranean world to save the planet.

When Anakin is forced to temporarily turn over command of his clone troopers to a new commander, the Jedi Pong Krell, tensions begin to run high as the clones are assigned with a very deadly mission to take the capital of Umbara.