Companion (Doctor Who) "Face the Raven", but in a subsequent episode ("Hell Bent") her time stream is frozen at the moment of death by the Time Lords so that they can interrogate her about the Hybrid; the Doctor takes advantage of this to save her life, but she remains technically neither alive nor dead, does not age or have a pulse. After her departure as a companion of the Twelfth Doctor, she teams with the immortal Ashildr and travels in a stolen TARDIS. Other companions died in alternate timelines or alternate lives. "Brigade Leader" Alistair Lethbridge-Stewart, "Section Leader" Liz Shaw, and "Platoon Leader"
Companion (Doctor Who) and "Battlefield". He and Sergeant Benton began as returning characters in the first place, having appeared with the Second Doctor in "The Web of Fear" and again in "The Invasion", prior to starting their full-time association with the Third and Fourth Doctors. Tegan Jovanka was the first full-time companion to part from the Doctor and subsequently return to full-time companionship, although the break in her tenure had been pre-planned. Most reappearances of companions in the original series, however, were for anniversary specials such as "The Five Doctors" and "Dimensions in Time", both of which also featured multiple Doctors. One former