Spearhead From Space Exiled to Earth by the Time Lords, the newly regenerated Doctor is enlisted by UNIT to combat an invasion by the formless Nestenes and their deadly Auton footsoldiers. Doctor Who and the Silurians The Doctor and UNIT are summoned to a subterranean research centre beneath Wenley Moor after it experiences mysterious power losses. The answer to the mystery lies in the nearby cave netwrok, where an ancient race of creatures is brought to life. The Ambassadors of Death Contact has been lost with Mars Probe 7. When the vessel sent to recover the crew return to Earth, the astronauts are kidnapped. Liz detects high levels of radiation in the space capsule, and the Doctor can only conclude that the occupants were not human.