OVERALL EPISODE NUMBER: 540
STORY NUMBER: 112
TRANSMITTED: Saturday 25 October 1980
WRITER: Andrew Smith
DIRECTOR: Peter Grimwade
SCRIPT EDITOR: Christopher H. Bidmead
PRODUCER: John Nathan-Turner
RATINGS: 5.9 million viewers
FORMAT: DVD: Doctor Who: The E-Space Trilogy (Full Circle / State of Decay / Warrior's Gate)
While travelling to Gallifrey the Tardis passes through something. The scanner shows them on Gallifrey but stepping outside they find themselves on a lush forest world. At a nearby riverside a group of teenagers are trying to steal fruit but witness the arrival of the Decider Draith & Dexeter who examine the fruit finding traces of an insect egg. The teenagers, a group known as the Outlers, retreat to their cave where their leader Vash is joined by Adric, his younger brother who wants to join them. They challenge him to steal the riverfruit. As he does the lakes start to bubble and a mist forms: the Mistfall that the Deciders fear. The Deciders summon their people back to the starliner giving them two hours to comply. Draith witnesses Adric stealing the fruit and pursues him. They tussle and Draith falls to the ground. Citizen Logan searches for his daughter, a member of the Outlers. Draith is sucked into the water instructing Adric to tell Dexeter they have come full circle. A fleeing Adric find the Tardis and is let on board by the Doctor & Romana. As they treat his injuries the Starliner is sealed with Logan's daughter and Decider Draith still missing. The Doctor & K-9 investigate the mist, and while at the waters edge witness creatures rising from it......
A bit of a game of two halves, with both halves being good. Firstly something has happened to the Tardis: it believes it's on Gallifrey when it obviously isn't. Secondly where they are has some odd stuff going on with mist and monsters suddenly appearing. Lots of questions.
This story was written by Andrew Smith, a teenage fan of the show, and is his only produced script for the series. It's also the debut of Matthew Waterhouse as Adric. Waterhouse was also a fan of the show, having a letter published in an early issue of Doctor Who Weekly (#3 if I recall correctly but seeing as the issue is in a box, in the loft and under my Big Millennium Falcon I ain't getting to it any time soon!).
Around the time this episode aired word leaked out to the press that Tom Baker would be leaving Doctor Who.