Sister Six

Sister Six was a female Xexto assassin who came to join a crew of mercenaries led by Chelli Aphra. Tasked with recovering memories of Aphra's superior, they traveled to Skako Minor to search the workshop of Wat Tambor. There, they were ambushed by an Imperial squad led by Magna Tolvan, which awoke a large beast. After eventually killing the beast, they looted the workshop and Aphra led them out.

The next destination for Six and the other mercenaries was the rebel flight school. There they were mistaken for recruits, before being imprisoned by General Hera Syndulla when she realized who they really were. They managed to break their prison shields, but did not try to escape, impressing Syndulla. When she came to listen to why the mercenaries were at the flight school, Syndulla was stunned by Sister Six, whom stunned the rest of the rebels in the room with her. The mercenaries then kidnapped Syndulla to use her as a bargaining chip to enter Hivebase-1.

Aphra's plan to infiltrate Hivebase-1 was successful in the fact they managed to get in undetected. They then conversed a room of rejected prototypes and after consulting with Tolvan by accident, Aphra managed to get their presence revealed to the Imperials. The prototypes were unfrozen and Six and the others took cover. Aphra used Caysin Bog as cannon fodder in order to have Tam Posla fight the prototypes for them. Six then followed Aphra and Syndulla to the Hivebase-1 datacore. Although they were attacked by more Imperials, Aphra managed to use her bugs to have the datacore ripped out of Hivebase-1.

Following the aforementioned events, Aphra, Six, Posla and Syndulla returned to the flight school and Syndulla congratulated them on stealing the datacore. Six decided to stay with the rebels while Aphra left with Posla.

Text and facts from the “Sister Six” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.