EPISODE: The Mind of Evil: Episode Five
OVERALL EPISODE NUMBER: 287
STORY NUMBER: 056
TRANSMITTED: 27 February 1971
WRITER: Don Houghton
DIRECTOR: Timothy Combe
SCRIPT EDITOR: Terrance Dicks
PRODUCER: Barry Letts
FORMAT: VHS: Doctor Who - The Mind of Evil [VHS] 
Episode Format: 16mm b&w film recording
The machine teleports away from the Doctor to go to feed on the more evil minds of the prisoners. The Master forces the Doctor to build a device to restrain the machine. The Brigadier works out the prison was involved in the missile hijacking and, using a food delivery van as a trojan horse, storms the prison. Mailer takes Jo & the Doctor hostage, but Jo tries to distract him so the Doctor can escape. Seizing Jo, Mailer trains his gun on the Doctor and a shot rings out.....
Another big action sequence in this episode as Unit troops storm the prison, and a surprisingly blood thirsty one too as casualties are suffered in some numbers by both sides. It's odd to see the Brigadier and co blazing away at other human beings rather than at monsters! We get to meet another of the Brigadier's deputies in this episode, the pretty useless Major Cosworth played by Patrick Godfrey who was Tor in The Savages.
As episode one of this story started Liz & I turned to each other and both said three words to each other before collapsing in a fit of giggles:Porridge has become such a definite work on the subject of prisons that it's hard to avoid mentioning it when talking about a show set in prison. Following a pilot, Prisoner & Escort, in the 1973 BBC series Seven of One which also spawned Open All Hours, three series and two Christmas specials were made by the BBC. Ronnie Barker is superb throughout ably backed up by Richard Beckinsdale. Several of the rest of the substantial supporting cast have got Doctor Who form: Fulton McKay, playing Mr Mackay, we saw recently as Dr Quinn in early episode of The Silurians. Tony Osoba, McLaren, is Lan in Destiny of the Daleks while the The Honourable Mr Justice Stephen Rawley is played by prominent actor Maurice Denham who is in the Twin Dilemma as Edgeworth. Incidentally the voice heard at the start of every Porridge episode sentencing Fletcher is Ronnie Barker himself! Brian Glover, Cyril Heslop, appears in Attack of the Cybermen as the crook Griffiths. The Governor of Slade prison is played by Michael Barrington who is Sir Colin Thackaray Seeds of Doom while it's Doctor is Graham Crowden, Soldeed in Horns of the Nimon. Prisoner Williams is Philip Madoc (Krotons, War Games, The Brain of Morbius & The Power of Kroll) while Jarvis is David Daker, Irongron in The Time Warrior & Captain Rigg in the Nightmare of Eden. Finally visiting prison officer Mr Wainwright if played by Peter Jeffrey, the Pilot in The Macra Terror & Count Grendel in The Androids of Tara.