The Android Invasion

The TARDIS lands on the planet Oseidon where a species known as the Kraals have created an exact replica of Earth. It is so realistic that the Doctor and Sarah have no idea they are not on Earth.

As they are walking around they notice a U.N.I.T. soldier stumbling towards a cliff, then plunge over the edge. They later see the same man in a pub.

The Doctor discovers that they are not on Earth, and that a human astronaut, Guy Crayford, has been assisting the Kraals. The Kraals plan to release a deadly virus on Earth, and are going to use the spaceship of Crawford to spearhead the invasion.

On Earth the Doctor and Sarah try to alert the troops at the Space Defence Centre of the danger. With the Brigadier in Geneva the warning goes unheeded.

The Doctor uses the centre's radars to jam the signals of the androids activated on Earth, and Styggron, leader of the Kraals, falls victim to his own poison.

• Guy Crawford: Milton Johns;
• Styggron: Martin Friend;
• Corporal Adams: Max Faulkner;
• Morgan: Peter Welch (1-3);
• Harry Sullivan: Ian Marter (2-4);
• RSM Benton: John Levene (2-4);
• Marshal Chedaki: Roy Skelton (2-3);
• Kraal: Stuart Fell (3);
• Colonel Faraday: Patrick Newell (4);
• Matthews: Hugh Lund (4);
• Grierson: Dave Carter (4 - also credited for 1 but does not appear);
• Tessa: Heather Emmanuel (4);


• UNCREDITED CAST:
• Android Mechanics: Derek Hunt (1-3), Roy Pearce (1-3);
• Farmer: Walter Goodman (1);
• Young Farmhand: Simon Christie (1);
• Barmaid: Margaret McKenchie (1);
• Tweedy Doctor: Freddie White (1);
• Students: Martine Holland (1), Mark Holmes (1);
• Double for the Doctor: Terry Walsh (2-4);
• Stuntman/Soldier: Peter Brace (2);
• Villagers: (all 3) Keith Ashley, Barbara Bermel, Martine Holland, Cy Town;
• Soldiers: Mark Allington (2-3), Alan Clements (1-3), Alf Coster (2-3), Derek Hunt (3), Richard King, Pat Milner (3), Roy Pearce (3), Christopher Woods (2);
• Walk-Ons: Lewis Alexander (1), Keith Ashley, George Ballantine (1), Simon Christie (3), Ian Elliott (1), Alan Jennings (1), Henry Lindsay (1), Sue Manners (1), Clinton Morris (1-3), Terry Walsh (2), Betsy White (1), Joan Woodgate (2);