The Mission to Mustafar was a mission carried out by Rianna Saren. After she learned that a new drug was used
on Mustafar to increase the slave production of mirkanite, a material used in construction of turbolasers, she went there to stop the production. She also hoped to find Zarien Kheev, a slaver who cut off her lekku.
Rianna and Zeeo infiltrated the facility and soon discovered that the mirkanite was delivered to Despayre and that Zarien Kheev wasn't on Mustafar. They continued their mission and soon found a group of Wookiee slaves who managed to escape. One of the Wookiees gave them access codes to the main computer. Using those codes Zeeo put the drill on overdrive. They also saw a hologram of Kheev hiring Boba Fett to track down Alderaan intruders. However, Zeeo discovered that Zarien had already departed for Tatooine. Rianna decided that her time with the Rebellion was over and followed Kheev there.
"We're going to Tatooine. No more Alliance, Zeeo. We've done all we can for them. It'll be just you and me."