Fourth Sister

The Fourth Sister came to Barriss Offee's prison cell with an offer to join a new service, the Inquisitorius. The prisoner recognized her as Lyn Rakish, whom she had known in the Jedi Order; after Order 66 Lyn had willingly chosen the dark side. The Fourth Sister took Barriss to Nur and, once the trials were over, handed her an Inquisitor's helmet.

When Obi-Wan Kenobi got into the Fortress Inquisitorius on Nur in 9 BBY and escaped again, neither the Fourth Sister nor the Fifth Brother managed to stop him. Earlier in the search for the Jedi she had been to Daiyu, escorting the Grand Inquisitor there with the Fifth Brother, and to Mapuzo, which she combed with other Inquisitors and Darth Vader.

Barriss left the Inquisitorius after the Fourth Sister slaughtered settlers who had deceived them and then, in the mountains, cut down from behind a Jedi who was ready to surrender; appalled, Barriss used the Force to hurl her off the slope. Later, tracking the Force-sensitive boy Micah on a snow-covered planet, the Inquisitor found Barriss guarding him. Barriss held her back while the family got away and warned her about an ice cave; lost inside it, the Fourth Sister lashed out in fury and accidentally ran Barriss through, then dropped her lightsaber and carried the wounded woman out.