Barring some plot points, this story is a classic.

I agree with other reviewers that this story is a comparatively weak entry for Season 18. However, compared to any number of stories from seasons 11, 15, 17, and 24, this one is superlative.

I'll start with the bad: The only thing fundamentally wrong with this story is that it does too many things without saying much about why those things happen.Yes, there apparently was a civil war on Zolfa-Thura regarding the Dodecahedron power source. We would like to know more about that as the emphasis on this story feels flat because of it. Meglos can change form and inhabit other creatures - is this related to the civil war or a natural trait? Why does Meglos need a human (non-Tigellan) to inhabit, what's so special about the Tigellans that they couldn't be used as hosts? Meglos' ability to control time is the one remaining factor of interest... he's able to be and do so much and the viewer isn't told anything as to why. Except for mentioning a war... We know the Dodecahedron energy source mysteriously landed on Tigella - could this power source have been a key reason for the Zolfa-Thuran civil war, based on some sort of morality? Who knows? We do know that the Deons, ruled by Lexa, claim the energy source to be given to them by the Gods. The Savants, scientists, don't believe in the idea that the Gods helped them out and wish to study the device. But are barred by the Deons. It's a straightforward example of a theocracy and manages to keep the viewer from thinking of WHY they got the device in the first place, but that is also an anti-climax.

In short, the story essentially begs for a prequel (unlike re-using the Autons as rumored for this new Dr Who TV series...).

Now for the good:

Tom Baker's cactus make-up is superlative and almost disturbing to look at, the idea was conveyed exceptionally well.

The direction and camerawork is pretty inventive at times too.

So is the model work, though upon repeated viewings some of the limitations become obvious. (But for a low budget show made in 1980 to compare with mindless fluff like "Buck Rogers", this stuff still looks very good for the time. And if you look at any Buck Rogers episode, it looks cheaply done too.)

Whatever else can be said for the plotline (it needs a prequel!), the music makes it all the much better. Fortunately, the soundtrack had been released on its own and is well worth the purchase.

K9 gets abused and kicked around.

Jacqueline Hill (original companion Barbara - 1963-1965) was hired to play Preistess Lexa. As a couple of companions had played unrelated characters in the past, I see no reason to say this casting was biased in any way. Indeed, she does quite a passable job in the role of Lexa.

Acting, overall, is rather good. Tom Baker, as in all of season 18, excels. I'd gotten very tired of the excessively comic style and producer John Nathan-Turner made the right decision to make him more somber. The entire season has this somber effect, though it was never explained why the 4th Doctor's persona changed. (an "untelevised adventure" featuring a significant defeat against the Doctor would readily explain the change in attitude.) If only Tom Baker stayed on, what would season 19 have been like?

All in all, this story is worth at least a rental. Far worse stories exist, and this story is not worthy of the low reputation bestowed upon it.

Not the best story of Season 18, but not unwatchable

Romana:"Oh blast! Here we go again!"
Doctor:"Now what's wrong?"
Romana:"Now his probe circuit's jammed."
Doctor:"Well, that's easy. Waggle his tail."
Romana:"All right. I've tried everything else."
K9:"Thank you mistress. Repairs complete."

Like Monty Python's "Deja Vu" sketch, that bit of dialogue gets repeated over and over inbetween Episode 1 and 2 of Meglos, when the title character traps the TARDIS in a Chronic Hysteresis, which is a time loop. Whether or not you like hearing the same bits of dialogue and action over and over will determine whether one will like Meglos. However, there are some slow parts and not many memorable characters--save Deedrix, Zastor, and Lexa--that don't make this an outstanding story. So, as the Doctor says, "first things first, but not necessarily in that order."

The planet Tigella is ruled by the elderly Zastor, who has to mediate between two factions--the Savants, or the scientific caste with their white one-piece body suits and blonde hair, who use the unstable Dodecahedron as their power source and the salmon and black-robed Deons, who worship the Dodecahedron. This conflict between rational and religious-minded people is universal, those who demand proof and those who believe. The Deons have an advantage, in that they believe it came from the heavens, where the Savants think it came from somewhere, anywhere, but not the heavens. To fix the instability of the Dodecahedron, and to placate both sides, Zastor calls on the Doctor, who's in orbit nearby. He describes him as the man "who solves the insoluble by the strangest means. He sees the threads that join the universe together, and mends them when they break." In other words, he has the "maturity to respect many points of view."

That twenty-sided object is the cause of all the fuss in this story. As part of a peace treaty ending the war between Zolfa-Thura and Tigella, the Dodecahedron was taken to Tigella. Ten thousand years later, Meglos, the last Zolfa-Thuran, enlists the aid of General Grugger and the Gaztaks, which isn't the name of a cheesy rock band but a band of marauding mercenaries for hire, to get the Dodecahedron. Meglos, having intercepted Zastor's invitation to the Doctor, impersonates the Time Lord.

There are some interesting bits. General Grugger's hat and costume are akin to a Tartar chieftain. The concept of unstable body transfer was also explored in the last Star Trek episode "Turnabout Intruder", but since when did Captain Kirk start turning into a humanoid cactus? Tom Baker's cactus makeup is quite a sight and fright.

Who fans will recognize Jacqueline Hill (Lexa, the leader of the Deons) as one of the First Doctor's very first companions, Barbara Wright (1963-1964). This was Hill's last Who appearance, as she died in 1993.

"Not impossible. Merely beyond your comprehension," says Meglos. As for this story, "not unwatcheable--merely away from greatness." I will say it's the worst story of the 18th season, but not all that bad.

Like Monty Python's "Deja Vu" sketch, that bit of dialogue gets repeated over and over inbetween Episode 1 and 2 of Meglos, when the title character traps the TARDIS in a Chronic Hysteresis, which is aEoh dear, I think I'm in a time loop. Help!

Revenge of the cactus face!

in my opinion this is not one of the best of Tom Bakers as are any of the ones from his last season.

A cuctus like creature takes over the body of a human who then impersonates the doctor sounds like something blake edwards would be better at writing. It was nice to see jacqueline hill,who played barbara all those years ago in the begining, have a big part in this one, however the rather silly special effects (including some very bad CSO effects) make this one a bit hard to give more than 3 stars.

I also has some problems with the video as it flicked at times and the picture became 'washed out' but i wasn't sure if this was a problem with this copy or with the release in general, and it was not bad enough to make me spend the time and effort to get a replacement only to find out it that every video was like that, so no biggie there.