Terry Nation is back, having certainly earned the invitation. Two stories in, Nation's tropes as a writer are starting to show. There are good things and bad things about his style of writing; the TARDIS crew seems like a close-knit family in his episodes, and he has a good grasp of the roles of each character. He is especially good at writing for the Doctor. This makes him good at those early exploration episdoes using just the regulars. He's good at putting creative obstacles in their way, which require them to think their way past them (there are plenty of examples here, but see also the escape from the cell in The Daleks and the discussion of static electricity). Finally, he's also good at ramping up the tension for a big finale.
Then there are his bad points. Susan tends to scream quite a lot in his stories, and she is perhaps at her worst here. When she's not around, Barbara fulfils the screamer role - why must there be a screamer? I was surprised Ian remained so patient with them throughout it, they were so useless. This is not a good story to show someone to quell the myth of all the classic series companions being helpless girls who scream and need rescuing all the time. His ideas are sometimes difficult to bring to life onscreen and his tendency to include as many sci-fi setpieces as possible stretches the budget to its limit and we end up with a finished product that looks deciedly B-movie-ish.
I quite like "quest" stories, actually, and like most of them, The Keys of Marinus is never boring. The pacing is too fast for that, unlike many 1960s stories, and the subquests are very different so if you don't like one you will might like the next one more, quite like the Key to Time series all in one story.
The plot centres on the TARDIS crew roped into helping Arbitan collect the keys of a justice machine, keys which are scattered throughout the planet Marinus. I quite enjoyed that their first instinct is to hop into the TARDIS and leave - it's believable that at this point they're a bit frustrated with being stuck wherever the TARDIS takes them. "The Sea of Death" sets up the story pretty well, and the conundrum of the glass beach and acid sea is genuinely interesting. Unfortunately, I get the impression that Terry Nation is writing to a formula here as while the discoveries of the first episode of The Daleks - the petrified forest, the dead metal creature - were relevant to the plot of the story, here the glass beach and the acid sea, despite being interesting at the time, turn out to be completely irrelevant. It also suffers in comparison because it looks cheaper and the direction is ordinary. It's nice to see a Voord examining the TARDIS but doesn't somehow prevent them from entering it - that would have been eye-rollingly predictable. Still, we get some cool invisible forcefield acting from the regulars and a pretty good cliffhanger, and Arbitan dying in the first episode is delightfully unexpected. Overall, a fun episode but hardly Doctor Who at its best.
The second episode is one of my favourites, although like most others, the limited time hurts it. The characters are hypnotised and think they're in a lavish city being treated like gods, but Barbara sees it is all fake. Making Barbara the only one not to be affected rather than the Doctor was a good choice, if only because the Doctor's reactions to his "laboratory" were hilarious. The episode goes through a usual four-story formula in 25 minutes, with the villain brains in jars being unveiled towards the end. And again like most episodes, there isn't time for anything but an instant solution to their problem. Barbara gives the brains a whack and suddenly everything's fine. Such a crappy solution is only going to annoy people who really liked the plot of that episode.
Unfortunately, the story starts to sag after that. "The Screaming Jungle", as great as it was to see Susan tortured by the sound of screaming (very post-modern), the rest of the episode is about as naff as Doctor Who ever got. First Barbara is kidnapped by a groping statue, them almost killed by unconvincing spikes that look like they're about to break off their hinges. This is one of the few episodes were Barbara is almost as annoying as Susan. The idea of a fast-growing forest is fascinating, if only it were given more time.
The fourth episode barely left an impression at all. We get a good villain in a nasty man who wants to rape Barbara, but the cave scenes brought back memories of the later episodes of The Daleks, and not in a good way. The Doctor is absent in Episodes 3 and 4, William Hartnell's first break from the series, and his absence reminds me how much presence he has on-screen. Never is this more clear when he returns in Episode 5, which introduces a Who-dunit scenario, with Ian accused of committing a murder while trying to commit a theft. Yet again, the main problem is that there isn't enough time to allow the situation to unfold at a natural pace - everything has to happen quickly - and so many characters are introduced suddenly that I was having a hard time remembering who was who, which is not something you should have to do in a Who-dunit, where the I would expect the writer to go to some effort to establish the key players and suspects.
The last episode is a good one. It was a good choice to let the trial story overrun into this episode, as it afforded us quite a good cliffhanger in a story whose cliffhangers were becoming predictable, and the Susan kidnap subplot was actually more interesting than Ian's trial itself.
I think the best thing about this story is its naffness. It would of course be a very poor choice to introduce someone to the show with, they need to come to terms with its low budget first, develop a love for it that renders cheapness irrelevant (unless it's REALLY bad, like the Myrka), otherwise they'll laugh all the way through it, at its expense. Once you develop that love, while you still laugh it's mainly out of affection. If nothing else, it's got a Voord dressing up as Arbitan, attacking leaves, moving walls and brains in jars, all delivered with total conviction, and all total rubbish - but Doctor Who is the only show I know that is brilliant when it's rubbish.
Horror quotient - No chance!
Comedy quotient - The Doctor gets quite a few good lines.
Drama quotient - A few moments aside, this is only one notch above The Chase for unintentional humour killing the drama. But to be honest, sandwiched between two of the greatest Doctor Who stories ever, drama wasn't going to be its forte even if Terry Nation did try harder to deliver the goods in that department. One thing I'll comment on though is in the previous stories we always knew where the main characters stood, their intentions and motives, but here they seem to meander from plot point to plot point solving puzzles. The actors do their best to communicate the character's feelings but Terry Nation isn't helping.
It's no classic, but if I want a good adventure story that will keep me entertained for a couple of hours, I can do a lot worse.