A legendary character in "Star Wars" movie and book lore is about to make her debut in the Disney XD animated series "Star Wars Rebels" -- and it spells bad news for the future of the evil Galactic Empire. A new clip from the upcoming "Rebels" episode "Secret Cargo" shows Alliance leader Mon Mothma calling upon the Ghost crew to help her get to a meeting on Dantooine.

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Mon Mothma has a storied place in the annals of "Star Wars" lore. She is the Senator from Chandrila that stood up to Chancellor Palpatine's push into fascism and she was instrumental in aligning the various grass roots rebel forces into the organized Rebel Alliance that would eventually bring an end to the Empire. Mon Mothma goes on to be the first Chancellor of the New Republic. The character debuted in 1983's "Star Wars: Episode VI - Return of the Jedi" and returned last year in "Rogue One: A Star Wars Story." Mon Mothma will be voiced in the episode by Genevieve O'Reilly, the same actress that portrayed the character in "Rogue One" and deleted scenes in "Star Wars: Episode III - Revenge of the Sith."

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“Star Wars Rebels” recounts the slow decline of the Galactic Republic in the wake of the Empire’s rise, and the subsequent fermenting rebellion. Taking place 14 years after the “Star Wars: Episode III – Revenge of the Sith” and five years before “Star Wars: Episode IV – A New Hope,” the series brings together a ragtag group of rebels who conduct covert operations against Imperial forces.

The “Star Wars Rebels” episode “Secret Cargo” airs on Disney XD this Saturday, March 4 at 8:30 p.m.