The penultimate story of the Davison era, Planet of Fire is an fairly entertaining four part romp which wasnt as good as it could have been. However it does execute its main agendas competently (the reappearance of the Master, the exits of Turlough and Kamelion, and the introduction of an new companion Peri), but it cannot be regarded as one of the highlights of the Davison era.
The location overseas filming on Lanzarote is nice if slightly bland, although it is clearly obvious that the locations on Sarn quite clearly appear to be the same as those of Earth.
The adventure starts off in the vein of most mid 80s serials, with lengthy scenes inside the TARDIS, with the Doctor still distressed about the events of Resurrection of the Daleks, and Turlough being disturbed by an distress signal of Trion origin, an recurring theme throughout this story, with Turlough being forced at the near end to finally stop running from his people.
Another recurring theme is Kamelion and the Masters usage of the robot throughout the story as an slave.
You dont know why the Master is forced to use Kamelion until later on at the cliff hangar to episode three, with the big payoff as the rogue Time Lord is seen miniaturized inside an control box of his TARDIS. The interior of the Masters TARDIS is disappointing, clearly being the same version of the Doctors but painted black instead of white.
I also found the plot fairly tiring and confusing at times, the natives of Sarn appear to be shallow and rather dull people, being led by Timanov, an pompous and fanatical religious leader.
It is also unclear whether newcomer Peri is actually in fear of her step father Howard, whom appears as one of Kamelions guises throughout the story.
Nicola Bryant does make an very good debut as Peri, and her infamous Bikini scene in Part One is in context, and adds much needed drama and increases the tempo of an slow episode when she is seen to be drowning, and Turlough has to go out and rescue her, one of the first times on the series where we get to see this normally cowardly and selfish character risk his life to save another.
Another observation for me is that in this story the 5th Doctor really lacked the strength and presence of the 3rd and 4th Doctors, and a lot of the time it is Turlough who is the commanding authoritative figure. Mark Strickson for mine puts in one of his best performances as Turlough whom finally faces up to his destiny and becomes an real leader for the first time, helping the survivors and his brother Malkolm return to Trion.
Another performer who excelled in this story was the late Anthony Ainley, easily giving his best performance as the Master since Logopolis with an classy and menacing performance as the Kamelion-Master for most of the story, and I do agree with the sentiments that the 80s Master looked far better in a business suit than that silly penguin outfit he was forced to wear so often.
With all those elements taken into account, this story should have come across as exciting and fast paced, but sadly due to an number of factors, the thinness of Peter Grimwades script (I think it lacked enough substance to sustain it for the four episodes) and the rather drab and uninspiring direction by Peter Moffat (just compare the direction of Planet of Fire to the following story The Caves of Androzani and see what I mean !!!) and some bland acting from some of the extras (although Peter Wyngarde is superb as the fanatical Sarn elder Timanov) and the general impression I get is one of disappointment. This story had the potential to be so much better, I think too much was made of the natives of Sarn worshipping Logar and the concept of the natives worshipping technology was covered far better in Face of Evil.
Its saving grace however is the nice and fitting departure of Turlough, and contains one of the best performances of the series of the late, great Anthony Ainley, and is an great tribute to his considerable acting talents.