In which Steed puts out a light, and Emma takes fright…
UNIT are called in when top secret plans and valuable equipment is stolen from high security establishments. The newly regenerated Doctor suggests that the thief may not be human.
The Doctor races to avert a nuclear holocaust. The robot, distraught over killing its creator, takes Sarah hostage and goes on a rampage.
Templar receives a request for protection from a beautiful girl (June Ritchie) claiming to be Hitler's daughter; guest Noel Purcell.
Using the deadly disintegrator weapon, the robot steals the destructor codes. Harry Sullivan is sent to infiltrate Think Tank to discover the truth.