The Republic and Gungan forces have been captured by Riff Tamson and his Karkarodon enforcers. Now, it is up to Ahsoka and the young Prince Lee-Char to unite the fractured people of Mon Cala and drive out the Separatist invaders.

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.