Pella is the main antagonist in the Blake's 7 episode "Power".
She was portrayed by Juliet Hammond-Hill.
Pella was the leader of the all-female Seska tribe on Xenon, who were at war with the male-dominated Hommicks. By the time, the Liberator survivors arrived on the planet, the Seska numbered only three: Pella, Kate and Luxia. Pella had been working with Dorian, who provided the Seska with nutrients for their hydroponic plant in exchange for technical assistance. Dorian believed Pella was helping him construct a working teleport. In fact, unknown to either Dorian or the other Seska, Pella was planning to steal his ship, Scorpio, the only way off the planet. She was constructing a tele-ergetron that would increase her telekinetic powers enough for her to open the silo to Scorpio. Like all Seska, she had been granted the powers by an implanted dynamon crystal.
Pella gained access to Xenon Base with her powers and met with Vila, who told her of Dorian's death. She similarly told him of the security around the Scorpio silo, most notably a nuclear compression charge primed to detonate if Dorian didn't reset it every 48 hours. Pella rejoined the other Seska but they were immediately ambushed by the Hommicks, and Pella and Luxia were captured.
Pella was imprisoned with Avon and they escaped together, partly down to Pella's surreptitious use of her powers. However, she was too late to save Luxia from having her crystal surgically removed. She and Avon argued over possession of it. Pella tried to use her telekinetic powers against him but his physical strength triumphed. He stumbled upon Cato, the only Hommick with technological knowledge, but Pella killed Cato by telekinetically firing Avon's crossbow. She then knocked Avon out with a levitated computer bank and took the crystal.
Pella rejoined Kate and they surreptitiously intervened in a duel between Dayna and the Hommick leader Gunn Sar, causing Gunn Sar's death. They then followed Tarrant, Vila and Dayna back to their base. Vila was able to remove enough of the silo door for the Seska to use their powers to disable the charge but Avon had lied about the code to the silo door, having realised what Pella was planning. Pella used Dayna as a hostage to force Avon to open the silo, killing Kate when she tried to intervene. Pella took off in Scorpio but Avon used Kate's crystal to complete the base's teleport system and teleport aboard. Pella fired at him but Avon returned fire and killed her.