The Sea Devils was the middle story of the 1972 season. The Third Doctor had encountered their land-based cousins, the Silurians, a couple of years before. This story is particularly memorable for two things: the glorious scene with the Master attempting to communicate with the Clangers, echoed thirty-five years on by his latest incarnation's encounter with the Teletubbies; and it is the first point where the Third Doctor actually does "reverse the polarity of the neutron flow", which became his catchphrase. Like all of the Pertwee six-parters I have seen, it drags a bit in places, and the two elderly male stooges (the jail governor and the parliamentary private secretary who is given improbably authority to authorise a nuclear strike on the monsters) are too two-dimensional to be credible. It's also disappointing that after his valiant efforts to make peace with the Silurians the Doctor decides to side with the stupid bureaucrats and destroy their cousins, after yet again the Master's non-human allies turn on him - will he never learn? The scenes of dead Sea Devils floating on the water are rather sad. But Katy Manning for once is rather good as Jo, with almost sensible clothes and rescuing the Doctor a couple of tines for a change. Also a shout-out to the silently feminist naval officer. No UNIT, slightly surprisingly, but otherwise a standard Third Doctor story.
If it hadn't been for the aforementioned hastiness of my packing, it would have been a lot longer before I got around to watching this, so bad is the reputation of the 1986 Trial of a Time Lord season among people whose opinions I generally respect (and the first four episodes totally failed to impress me). But actually "Mindwarp" was really rather good, and it's no wonder that Colin Baker wrote a sort-of sequel; Brian Blessed does his shouty thing, but the return of Sil from Vengeance on Varos, the horror of having Peri's brain wiped, the Doctor's confusion as seen on Thoros Beta, and the way in which the plot, uniquely in this season, is well integrated into the overall Trial of a Time Lord concept make it, I think, the best Sixth Doctor story I've seen. This is not especially high praise: I remember catching The Twin Dilemma, Vengeance on Varos and The Two Doctors first time round, and recently watched Revelation of the Daleks, listened to Slipback and of course now have caught up with the whole Trial of a Time Lord; even so, I doubt if the remaining three stories will surprise me with their brilliance as this did.
Having said that, the next segment of the Trial of a Time Lord season, "Terror of the Vervoids", is also not as bad as I expected. New companion Mel appears out of nowhere, looking remarkably like Bonnie Langford, and the head biologist on the spaceship looks remarkably like Honor Blackman. The Doctor's grief for Peri, the style of the Agatha Christie-type murder mystery, and the sense that this is a future environment that the Doctor is familiar with, all add a certain depth to proceedings. One could forgive the fact that the plot doesn't really make a lot of sense if it were not for the Vervoids themselves which are, alas, terrible rather terrifying; they are very nearly as awful as my personal candidate for worst Who monster of all, the giant mushroom creatures in the jungle seen in latter episodes of The Chase. On top of this the Doctor once again (as with the Sea Devils) simply wipes them all out; the Valeyard is right to ask for some kind of accountability for this act of genocide, though of course the whole courtroom scene as shown here is a pretty stupid forum in which to do so. The serried ranks of Time Lords in full regalia turning to watch the screen are particularly silly.
Sadly, there is nothing to be said in favour of the last segment of the Trial of a Time Lord, two episodes credited to three writers, a botched farrago of half-baked Time Lord lore, where we find out that the Valeyard is a projection of the Doctor's future self, and he and the Master take it in turns to do the evil cackle. The Time Lords have forgotten who the Master is, despite what happened in The Deadly Assassin and their summoning of his aid in The Five Doctors. The means available to the Master and the Valeyard are conveniently immense and yet just not quite immense enough to destroy the Doctor. I am even a bit dubious about Peri's survival, which rather critically undermines the drama of her death (and the chemistry between her and King Yrcanos was as absent as that between Leela and Andred - at least Susan, Vicki and Jo got decent parting romances.) It's a shame that after delivering so many classics Robert Holmes' final contribution is such a dud, adn the Sixth Doctor, having won his trial, then gets regenerated anyway. The miracle is that the show was allowed another three years after this awful closure to an over-ambitious season.
The Happiness Patrol, from the dying days of 1988, is a fairly standard rebels against the system story, lifted by some fairly memorable characters and concepts - especially Sheila Hancock as the dictator, and her vicious pet Fifi. It comes close to looking convincing - the coherent style of the Happiness Patrol themselves is almost genius. I started off being quite impressed by how well the Candyman worked, but I had completely gone off him in the end, and the musician and the census official, while nice touches, didn't quite seem to integrate into the whole thing. Not awful, but definitely not one of the great ones either.
So in summary, "Mindwarp" was an unexpected pleasure, The Sea Devils, "Terror of the Vervoids" and The Happiness Patrol all had their strengths and weaknesses, and "The Ultimate Foe" is best forgotten.