First Doctor, 1966, story 39, The Tenth Planet.
(Significance) first regeneration.
EPISODE 1
The Snowcap space tracking station based on the South Pole is monitoring the launch of the manned Zeus IV atmospheric testing probe as it goes into orbit. The ship is manned by two pilots, Schultz and Williams.
The Doctor, Ben and Polly materialise outside the underground bunker of Snowcap and are soon spotted by men watching the surrounding areas through a periscope. Men are scrambled out to collect the strangers. The Doctor, Ben and Polly willingly enter Snowcap.
Inside Snowcap the Doctor, Polly and Ben are interrogated. General Cutler is sent for, who responds hostilely to the strangers. Cutler decides to put them in the observation room until he has time to deal with them later. Once there, the Doctor notices a calendar on the wall saying it is December 1986. Ben is disappointed he won't be able to meet up with his ship but seems more interested when he discovers that space travel is the norm. This conversation is interrupted by a distress call from the Zeus IV space capsule which has been drawn off-course by an unknown force that drains the energy.
The pilots of Zeus IV explain that it is nowhere near the destination in which they would expect to be. Observing their location, Schultz sees another planet. Williams confirms this and says it seems to lie between Mars and Venus. Their state is also brought into confusion by the fact that the communication to Snowcap is weakened and their fuel is dropping much faster than normal.
Observing the crisis, the Doctor announces that he believes he knows the cause of the problems. He is not listened to but gives a piece of paper to Doctor Barclay. Snowcap sights the new planet before they receive the call from Zeus IV saying their fuel has reached 20% - Barclay says they should attempt to come down.
Schultz and Williams attempt to land, but they have no control over their descent as the new planet is affecting their gravitational pull.
Exasperated, Barclay goes to the Doctor for advice. The Doctor looks at a screen with the planet on it and observes that it is identical to Earth - down to the landmasses. The Doctor asks Barclay to look at the piece of paper that he had given him, and Barclay is astounded to read that the Doctor had predicted this phenomenon before they had even seen it. The Doctor tries to explain how he knew this, saying that millions of years ago there was a twin planet to Earth. Before he can go into any more detail, Cutler storms out, saying, "This is ridiculous." When alone, the Doctor explains to Ben that he fears this means invasion.
Cutler speaks to Mr Wigner, the Secretary General of International Space Command, and informs him of the new planet as well as the strangers. Wigner demands that they be interrogated immediately.
Cutler storms in and demands the truth from the Doctor; he suspects him of being involved in this mystery. He sends men out to search the TARDIS.
The men scramble to the TARDIS. Before they can get out, a mysterious ship lands on the surface of the South Pole. Unable to open the TARDIS, a soldier sends his ally back to get a welder. Whilst alone, he is approached by a robotic creature who knocks him out. When his ally returns, the creature is disguised in the man's clothes. When he turns to reveal himself, he knocks the two men out using human hands.
EPISODE 2
The Doctor reasserts his belief that there will be visitors to Earth from the mystery planet but is pooh-poohed by Cutler. Cutler speaks to Zeus IV and promises the pilots they will be brought back safely.
Outside Snowcap, the robots disguise themselves in the clothes of their now-dead victims.
At International Space Command, a powerless Wigner is forced to watch the news to learn about the mystery planet as communications have been severed with Snowcap.
