A weather balloon, with equipment, returns to Earth. Doctor Tyler is called, and the local warden goes to fetch it, but disappears. When Doctor Tyler starts to examine the equipment he gets some strange results, and he takes his findings to U.N.I.T. The Doctor examines the slides, and finds a strange effect.
Later the Doctor and Jo are besieged by a strange entity, and they manage to escape to the safety of the TARDIS, along with the Brigadier who has never been inside. Fearing that it may be too much for him the Doctor signals Gallifrey for help, but they are suffering from a power drain and are unable to help.
They do manage to obtain enough energy to break the first law of time and send the Doctor's 2nd incarnation to help, but the two only argue. Using the last remaining energy the Time Lords send the Doctor's 1st incarnation, although he is trapped in a limbo and can only advise from the scanner.
Together the Doctors realise that the entity is from an anti-universe, and the third Doctor and Jo, and later the second Doctor with U.N.I.T. HQ cross over to a black hole where they find a legend of the Time Lords - Omega. Omega is unable to escape from the black hole, and hopes to use the Doctors. However, together they manage to defeat Omega, and return everyone before the black hole is destroyed, restoring power to the Time Lords.
Regular castBrigadier Lethridge-Stewart: Nicholas Courtney; Sergeant Benton: John Levene; Jo Grant: Katy Manning;
Guest castThe Doctor: William Hartnell, Patrick Troughton; Doctor Tyler: Rex Robinson; Arthur Ollis: Laurie Webb; President of the High Council: Roy Purcell; Time Lord: Graham Leaman; Chancellor: Clyde Pollitt (1-2); Corporal Palmer: Denys Palmer (1-2); Mar Ollis: Patricia Pryor (1,4); Omega: Stephen Thorne (2-4);
Uncredited cast: Omega's Champion: Alan Chuntz (3-4); Gell Guards: Murphy Grumbar, John Scott Martin, Rick Newby, Cy Town; Time Lords: Peter Evans, Tony Lang, Richard Orme, Lincoln Wright;
|BBC 1||330||Episode One||Sun 31 December 1972||5:50 pm - 6:15 pm||9.6M||41st|
|BBC 1||331||Episode Two||Sat 6 January 1973||5:50 pm - 6:15 pm||10.8M||22nd|
|BBC 1||332||Episode Three||Sat 13 January 1973||5:50 pm - 6:15 pm||8.8M||44th|
|BBC 1||333||Episode Four||Sat 20 January 1973||5:50 pm - 6:15 pm||11.9M||17th|
Repeats (on the BBC)
Denham, Bucks; Springwell Reservoir, Rickmansworth; Summerfield Bungalow, Springwell Lane, Rickmansworth; YMCA/Minstry of Defence Hotel, Hayling Rd;
Ealing Film Studios; Television Centre Studio 1; Television Centre Studio 8;
Bloopers and mistakes
Episode 1: The recorder appears on the TARDIS console before it is heard materialising.
Episode 1 & 3: Katy Manning does it again. First, when the Gell Guards come out of the drain, the Doctor tells her to back slowly behind the car. Instead she jumps over the seat. When she is doing it, the back of her mini-skirt lifts up. You can see her light blue knickers clearly. And secondly, when they escape from Omega's castle, she comes down a hill a bit too quickly.
Episode 1 - 4: If the scanner is mounted on the TARDIS, whenever the scanner is used it shows a picture of the lab with the TARDIS in one corner, how can it be in the picture?
Episode 2: When Bessie is seen for the first time in anti-land, look at the tyres. You can see the dust from the ground all over them as if the car had been driven. But in the story it was supposed to have been teleported.
Episode 2 & 4: You can see the reflections of some camera crew in the monitor used to display the First Doctor.
Episode 2 - 4: When Omega is looking at his magic screen you can see the outline of the actual television set at the edge of the image.
Episode 3 & 4: At various times throughout the story Stephen Thorne's (Omega) lips are visible, and in one profile shot so is his jaw, yet when the mask is removed, we find that Omega has been dissipated.
Episode 4: During the scene when all the companions are returning to Earth via the pillar of smoke, you can see and hear each person walk up the stairs to the pillar of smoke. Although they disappear, you can clearly hear them walk down the other side!
Notes and trivia
This was a 10th anniversary story although it was shown some ten months early.
This is story has a copyright date for 1973 even though Episode One was transmitted during 1972
This programme has no other working titles, or they have not been yet been entered.