Inferno – 1970 – S7 – E4/4

image Number : Season 7, episode 4 of 4.

Which One : Who does the evil alternate reality.

Cast : The Doctor : Jon Pertwee
Liz Shaw : Caroline Johns
Brigadier : Nicholas Courtney
Sergeant Benton : John Levene
Professor Stahlman : Olaf Pooley
Sir Keith Gold : Christopher Benjamin
Petra Williams : Sheila Dunn
Greg Sutton : Derek Newark
Bromley : Ian Fairbairn
Harry Slocum : Walter Randall
Private Wyatt : Derek Ware
Private Latimer : David Simeon
RSF Sentry : Roy Scammell
Patterson : Keith James

Written By : Don Houghton

Produced By : Barry Letts

First UK Broadcast : 9 May – 20 June 1970.

Length : 7 x 25 minute parts.

Plot : In the midst of a dangerous drilling experiment, the Doctor is thrown into an alternate reality, where a facist paramilitary UNIT rule over a totalitarian British republic.

Whats good : Fun parallell reality tale. UNIT characters play evil.

Whats bad : Green goo – ‘Primord effect’ isn’t explained. The Primords 50’s Werewolf look.


Review With Spoilers : Inferno is the 4th episode of season 7 and the season finale. It also marks the final appearance of companion Liz Shaw.

Following some experiments on the Tardis console, to unlock the Tardis’ travelling ability. The Doctor is accidentally thrown into an alternate reality, where UNIT are a facist secret police; presiding over a totalitarian state and ran by the scar faced, eye-patch wearing – ‘Brigade Leader’ – Lethbridge Stewart.

A drilling experiment (in both realities) to unlock new frontiers in energy production from the Earths crust – threatens; as the resulting byproduct of the drilling – a green goo. Which regresses people into an animal-like ‘primordial’ states.

Inferno seems to parallell itself – the Original Star Trek episode Mirror Mirror, in which Kirk is thrown into a similar alternate reality with a warlike empire – ruled by an evil Spock. In Inferno, the Doctor becomes the Kirk character and the Brigadier is the Spock character.

It’s a classic sci-fi scenario and shifts quite easily into the Who format. The best thing about it is that the other characters get a rare opportunity to play baddies. Out of these, the Brigadier and Liz Shaw seem to have the most fun, playing evil alternate version of themselves.


“Same time, same place, only a different dimension. It was a parallel world, Liz. Terrible things are happening there. Terrible things! It wasn’t this Earth, and yet it was. I didn’t go backwards into the past, or forwards into the future. I slipped sideways!” The Doctor

The best scenes are the ones where the Doctor is first catapulted into this reality and unaware anything has changed, runs into his alternate UNIT comrades one-by-one.

Coupled with this, is the impending threat from the drilling project which threatens to overrun the surface with lava and spread a contagious green slime which reverts humans back to a primordial form.

The mechanics or reason for this green slime is never really explained. Neither is the ill-advised bizarre 1950’s B-movie Werewolf look, which the infected characters – ‘regress’ into.

The ‘Primords’ (as they are known) are only really here as a final act – plot shaker, to raise the stakes as they multiply and overrun the drilling operation; also ticking the box as the episodes token – “featured monster”.

But the real strengths of this episode is in the alternate reality format and the principal casts performances as their evil selves. Alternate Liz Shaw, in particular – is highly effective and some good interplay between her and the Doctor ensues. As he attempts to persuade her to help stop the drilling.

Inferno is a fun and simple parallell universe tale, which works so effectively – due to the high standard of the supporting cast. The Primords are clunky and less effective and the story didn’t actually need them. However, they are a minor distraction in a fun and entertaining crossed reality tale.

🔵🔵🔵🔵⚪ (4/5)

Old Doctor Who