: The R1C is running out of power and its crew has been regenerating for centuries to survive. The episode concludes as the ship heads toward a nebula where a new planet is forming. Viewing & Production Details
: This story is notable for its heavy use of early blue-screen technology (Chroma Key) to create the vast, cavernous underground settings. "Doctor Who" Underworld: Part One (TV Episode 1978) - IMDb [S15E17] Underworld 1
: Stars Tom Baker as the Doctor and Louise Jameson as Leela. : The R1C is running out of power