Astrid Ferrier was the daughter of Jean Ferrier, and after her father's murder (PROSE: Doctor Who and the Enemy of the World) became Giles Kent's assistant in his plot to take down Ramón Salamander. In 2018, she convinced the Second Doctor to help by impersonating Salamander.
Astrid rescued the Doctor, Jamie McCrimmon and Victoria Waterfield when they were attacked by three armed men. She introduced the Doctor to Kent. She helped Jamie and Victoria to infiltrate Salamander's headquarters. Their mission was to rescue Alexander Denes. They failed, and Astrid escaped, Jamie and Victoria were captured and Denes was shot and killed.
She met with Salamander's assistant, Fariah Neguib, who was willing to provide information proving Salamander's intentions. Salamander's guards broke in, killing Fariah. Astrid escaped and hid near a cave, where she found the body of Swann, one of Salamander's scientists. She found the rest of the scientists in their underground complex. She learned the truth about Kent and helped the underground group to safety when Kent blew up the caves. (TV: The Enemy of the World)