Karla was a member of the Celestial Intervention Agency. She informed Narvin and Romana II of the destruction of Phaidon. She helped Narvin to give Leela an override to a War Council facility. (AUDIO: Celestial Intervention)
She later became the liaison between the CIA and the War Council. She wanted to make sure that there was cooperation between the two agencies. She informed Narvin and Romana that Narvin that he was to be conscripted. She went with him to the Death Zone and eventually to Project Revenant. She was working in league with Livia and left Narvin to die in the explosion. She sacrificed her life to allow Rassilon's resurrection. (AUDIO: Desperate Measures)