The TARDIS lands on the planet of Spiridon. The Doctor has fallen into a coma, and his body temperature is so low that he has started to freeze. Unsure what to do Jo ventures out into the Spiridon jungle in a search for help. She meets up with a group of Thals. They leave her in the safety of their crashed spacecraft whilst they go to aid the Doctor.
The Doctor recovers, and learns of the Thals' mission to visit Spiridon to destroy a party of Dalek who are on a mission to learn the Spiridon's secret of invisibility.
The Thals are under the impression that they are hunting a small party of Daleks, and with communications down another Thal expedition lands with news that there are considerably more than that: somewhere there are around 10,000 Daleks.
The Doctor, with the aid of the Thals, find the Daleks waiting for activation. With the help of a well planted bomb the Daleks are entombed in an ice flow. The remaining Daleks are left stranded when the Thals use the Daleks' ship to leave the planet.
Regular castJo Grant: Katy Manning;
Guest castTaron: Bernard Horsfall; Codal: Tim Preece; Vaber: Prentis Hancock (1-5); Rebec: Jane Howe (2-6); Wester: Roy Skelton (2-3,5-6); Daleks: (all 2-6) John Scott Martin, Murphy Grumbar, Cy Town; Dalek Voices: Roy Skelton (2-6), Michael Wisher (2-6); Latep: Alan Tucker (3-6); Marat: Hilary Minister (3); Dalek Supreme: Tony Starr (6);
Uncredited cast: Dead Thal Pilot: Alan Casley (1); Spiridons: David Billa, Gary Dean, Terence Denville, Ronald Gough, Kevin Moran, Kelly Varney, Geoff Witherick;
|BBC 1||344||Episode One||Sat 7 April 1973||6:10 pm - 6:35 pm||11.0M||9th|
|BBC 1||345||Episode Two||Sat 14 April 1973||5:50 pm - 6:15 pm||10.7M||18th|
|BBC 1||346||Episode Three||Sat 21 April 1973||5:50 pm - 6:15 pm||10.1M||26th|
|BBC 1||347||Episode Four||Sat 28 April 1973||5:50 pm - 6:15 pm||8.3M||29th|
|BBC 1||348||Episode Five||Sat 5 May 1973||5:50 pm - 6:15 pm||9.7M||21st|
|BBC 1||349||Episode Six||Sat 12 May 1973||5:50 pm - 6:15 pm||8.5M||24th|
Repeats (on the BBC)
Beachfields Quarry, La Porte Industries Ltd., Cormonger Lane, Redhill, Surrey;
Ealing FIlm Studios; Television Centre Studio 3;
Bloopers and mistakes
You can see the strings that lower the door of the Dalek ship.
Despite being light years away from the nearest salon, Jo's hairstyle mysteriously changes halfway through the story.
The pots of the exotic Spiridon jungle plants are clearly visible in several shots.
Episode 1: After the Doctor recovers from his coma, he gets up and stands at the console. If you watch the central column at this point, you can see (in one of the mirrored surfaces) a reflection of one of the production crew moving around.
Episode 2: As the Doctor is being escorted out of the lift in the underground complex, watch the Dalek as it passes through the door - it bumps into the side with an audible thud!
Episode 2: When the Spiridon is treating Jo's infected arm, have a look on the ground - you can see the shadow of whoever is holding the bowl: Spiridons are supposed to be invisible!
Episode 2: The rock that hits Jo on the head is so large it should\'ve crushed her skull like a grape or at least caused major concussion. Also notice that Katy Manning obviously knows she's going to be struck on the head, and blinks uncontrollably just before it strikes.
Episode 3: When the Doctor and co. escape up the shaft with the aid of a giant hankie, the Dalek that they send after him has a blatantly obvious string attached to its top.
Episode 4: Vicious Spiridonian jungle animals have surrounded the Thals' fire encampment, but their silhouettes are clearly cardboard cut-outs with glowing lights for eyes. When the Thals shoot and scare off the animals, the eye lights go off, but their silhouettes clearly remain!
Episode 5: In the scene when the Daleks enter the rock circle (where Jo and the Thals have been hiding), watch one of the Daleks as it glides straight into one of the rocks - which can then be seen and heard scraping across the studio floor!
Episode 6: The Supreme Dalek seems to have a few problems with its eyepiece, which lights up in a similar way to the normal Dalek voice-indicator lights whenever the Dalek talks. The problem is that it also seems to light up when other Daleks are talking as well!
Notes and trivia
Episode Three only exists as a black and white film print.