TARDIS Crew: Fourth Doctor (Tom Baker), Sarah Jane Smith (Elisabeth Sladen), and Harry Sullivan (Ian Marter).
The Plot: Having just not prevented the Daleks from ever being created (whoops), the Doctor, Harry, and Sarah find themselves on what is basically a space lighthouse established to keep passing spaceships from crashing into a recently discovered asteroid. Well, the asteroid is actually the remains of Voga, the fabled planet of gold, and the plague that has stricken down most of the space station crew is actually poison spread by Cybermats, the weird metal caterpillary pets of the Cybermen, who want Voga destroyed once and for all because gold is basically their Kryptonite (or, more accurately, their peanuts, assuming they have a peanut allergy in this particular metaphor). There's a guy on the station who seems to be selling out the humans to the Cybermen, but he's really working for the Vogans, or at least a faction of them, because there's a minor civil war erupting down there and... oh, there's just a lot of running around and people getting shot at like every other "base under siege" story. Basically, what's most important here is that Harry Sullivan is an imbecile.
The Thoughts: In The Discontinuity Guide, Paul Cornell, Martin Day, and Keith Topping have a bit of a field day with this one, pointing out the many, many logical fallacies and just plain ridiculous plot holes - the biggest one, of course, being that the Cybermen are easily taken out by just a handful of gold dust, but somehow they are able to walk around inside a planet made of pure gold without any problems whatsoever. But while deep in my heart I know they're right, and that this is a ridiculous, stupid story, I still love it, and I cannot view it objectively at all. this was the very first Doctor Who story I ever watched (rented the early VHS version of it from the video section at Dunnett's Appliance Store in Bangor, ME, when I was maybe 8 or 9), and I thought it was cool enough to give watching it regularly on PBS, where I quickly became hooked, and my Saturday dinner-time TV plans were settled for the next several years.
Watching it now on DVD, the first time I've seen it in many years, I can see the problems Cornell and co. point out, but I thought it was still too much fun for any of that to bother me. I just can't bring myself to be bothered by the Vogan make-up that muffles every spoken word, Cybermen decked out in accordions and vacuum clearner hoses, recycled NASA stock footage, or Harry Sullivan's ascotted incompetence.
And oh, Harry Sullivan. A relic of an older time on Doctor Who, a period when the Doctor was an older guy who couldn't run around all the time, and so they had to bring in a younger guy to handle the action scenes. Ian Chesterton, Steven Taylor, Ben Jackson, Jamie McCrimmon... Harry was supposed to be the heir to their tradition. But Jon Pertwee never needed anyone to handle his action (in fact, he was probably the most hands-on Doctor of all), and Baker, being even younger, didn't either. But I've read that the producers originally did consider some older actors at first, and invented Harry as a response, albeit one that became obsolete the second Baker arrived, scarf-in-hand. So poor old Surgeon-Lieutenant Sullivan was just kind of... there, a fact they even worked into the scripts; the Doctor and Sarah seem to like him well enough most of the time, but they make it very clear he's cramping their style. Harry Sullivan... the Mickey Smith of the 70s in many ways. Sorry there, old chap. Stiff upper lip and all.
(Incidentally, Ian Marter, the actor who played Harry, did play the part well, and he was a decent writer, to boot, penning a few of the series novelizations for Target Books and a Harry-centric novel from their short-lived "Companions of Doctor Who" series, and I was very sad to hear about his death in the 1980s, so don't think I'm speaking ill of the man himself.)
As for the Cybermen themselves, well... this isn't a high point for them. There's only 3 or 4 of them, they're written as wildly out of character based on everything we know from other stories (way too emotional), and they look silly as hell, especially with the forehead-mounted guns. The script addresses this a bit, letting us know that these are the Cybermen on the ropes, having been nearly obliterated in war several centuries prior, and are now scraping to get by and gain their titular revenge on humanity and the Vogans, but even amidst all that, they come off as cheap and weak here. It wouldn't be until Earthshock several years later that they would become the menace they once were back in the Troughton era.
But it's still a damn sight better than Attack of the Cybermen. Even if I had hated it this time around, Revenge would still have that going for it at the very least.
Overall: Revenge of the Cybermen has plenty of problems, and plot holes you could guide an elephant parade through, but if you can let your inner 9 year old take over your mind for four episodes, you'll probably think it's pretty fun.
One Final Question: Why is everything on Voga plastered with the Seal of Rassilon, symbol of the Time Lords' High Council? Someone has to have explained that in a spin-off novel by now, official or otherwise, right?