"You're trapped in a temporal paradox! Styles didn't cause that explosion and start the wars - you did it yourselves!"
IN THIS ONE... The rebels caused their timeline by trying to prevent it, so it's UNIT against Daleks and Ogrons on the green.
REVIEW: Despite time travel or time anomalies showing up in various stories to date, this is the first true Doctor Who tale that deserves the now-popular appellation "timey-wimey". The rebels have come back in time to kill Sir Reginald whom they believe blew up a building full of delegates, causing WWIII, which killed off 7/8th of the population, leaving Earth ripe for Dalek conquest. As it turns out, they're the ones who blow up the house and caused their own timelines. Completely bonkers even now, but it's rather wonderful and clever at the same time (even if it's pretty obvious their interpretation of events is all wrong). Of course, there are still a couple problems with the plot. One is that the Daleks claim to have changed history, but plainly haven't (they also proclaim they've discovered time travel as if The Chase and The Daleks' Master Plan haven't happened yet, update your Dalek timelines). Unless they saw Earth's world war in their past and went back to exploit it. I guess that's it, but it's not really explained (also, see Theories). The second problem is that writer Louis Marks gave us a weird scene in Part 1, with the Doctor and Jo's temporal doubles, and never pays it off. How hard would it have been to have the two of them to return to the wrong moment, say before the final battle? As it is, those doubles came from nowhere.
It's the big action finale, but sadly, director Paul Bernard's last good fight is still the Doctor beating on a rebel while drinking wine. There, it's fun because he's supposed to be blase. But every other action scene is done like that, with stunt people sleepwalking through them. There's just no energy! Everything is slow and deliberate to the point of absurdity. We get UNIT soldier raising their arms slowly as they get exterminated. Completely ridiculous. We get a line of Ogrons and Daleks advancing with no strategy whatsoever as soldier shoot at them, and it's BORING. Victims drop to the ground without so much as an expression. Sure, there's a big explosion at the end - because, you know, UNIT era - but for a slam-bang finale, it's very limo. Yet, see Versions.
So what's to like aside from the paradox convolutions? Well, the future is well rendered, with descriptions of the Daleks depleting Earth's natural resources to build their Empire, and features a nice solution to the problem of future furniture (people sit on the floor, a sign that the Daleks find chairs irrelevant). The Controller is saved by the Doctor, so he repays him in kind and attracts the Daleks' ire. So we have a nice lesson about showing compassion even to a collaborator who likely had little choice, while also having that character punished for the crimes he committed. And the Brig pulls rank on the pompous Sir Reginald, always good for a laugh. The episode lives in these little moments, not on the larger set pieces.
THEORIES: Another concept that's mentioned, then abandoned, is the Blinovitch Limitation Effect, which apparently prevents you from interfering with your own timeline. The Daleks are crazy enough to try it, and in this case, have created a timeline they know to be different than their own history of the Invasion of Earth in the 2260s. You can't do that without calamitous repercussions, or so we've been led to believe. So in trying to do so, did they shunt themselves into a parallel world instead? We know from Inferno that it's possible. History or the time vortex or even the unseen Time Lords may be protecting the Web of Time by pushing would-be interferers to dimensions where a paradox would not occur. In this case, a world where Earth knows a third world war and the Daleks never swooped in as per their second appearance on the program. If I'm right, we still have to explain how these people wind up in OUR timeline, but I think it's acceptable (it is on Star Trek, for example, and in X-Men comics) that any given possible (usually called "alternate") future has access to the same past (a time before the turning point that led to that future). You might say there's an accepted future history in the Whoniverse (or else the Doctor couldn't return to Peladon or New Earth so readily), but we're often told that an invasion of Earth CAN and WILL interrupt the future development of humanity and must be fought. The Doctor even shows Sarah Jane the consequences of not acting in Pyramids of Mars, and that surely is an "alternate future" (or present, from Sarah's perspective). All of which doesn't make it any less bonkers.
VERSIONS: There's a Target novelization that features the cut scene where the Doctor and Jo double back on themselves (the other side of the scene in Part 1), and the Japanese edition does have pictures of a futuristic four-wheeled bugger instead of the motortrike featured on the show. The DVD also features a "special edition" version of the four episodes, surprisingly not consolidated into a single film-length story (as was done with several other Doctor Who stories). I must say it fixes a lot of the technical problems and creates a tighter, more exciting narrative. It can't help with the plot problems, however. So what's changed? Nick Briggs, the voice of the new series Daleks, re-dubbed all the Daleks, bringing to it a much richer (and on-model) performance. The action scenes are all much better thanks to the inclusion of ray beams coming out of the disintegrators and shockingly violent effects when they hit. The disintegrators seem to make people explode (that's not always flying mud, is it?), and the Daleks' exterminators have that tell-tale skeleton effect. Even UNIT has gotten a boost, with digital sparks and squibs going off all over the place. And lots of smoke. Now the fights take place in veritable war zones, and when that line of Ogrons and Daleks advances, they're brushing off bullets and appear intimidating rather than tacticless. It's not just CGI either. They even filmed little pieces of action with UNIT soldiers, Ogrons and Daleks, replacing some of the more rubbish bits. When there is a lot of CGI, it does tend to clash with the material around it, like the animated screens in the fascist HQ, or the admittedly cool establishing shot of the future buildings, with saucers overhead. The kind of energy bubble surrounding the portable time machines feel like a Terminator reference, which would be cool given how much that film series would seem to owe Day of the Daleks. Watching the making of the Special Edition, there are a lot of very small changes you might not even notice. They've eliminated line fluffs and camera shakes, redone a lot of the sound design, and tightened up the limp action considerably. One place I do think they failed is with the cliffhangers. Except for Part 3's (which features better and more animated shots of the two previous Doctors), they weren't able to eliminate the stupid reprise sting entirely. They cut out of it quickly, but it's still there and a major annoyance. Still, unless you're a purist, you'll find the story much more enjoyable with these new effects, sounds and edits.
REWATCHABILITY: Medium - As I feared, many questions left unanswered, and unless I'm watching the special edition, it ends with a big inaction set piece. However, the timey-wimey idea is clever, even if it does throw up even more questions.
STORY REWATCHABILITY: Medium - An intriguing temporal paradox, but not much else. The editing has something to say, but the action scenes are universally terrible, and the two middle episodes are at a standstill. Part of the problem seems to be that the Daleks weren't in the writer's original draft, so their big return (in color!) doesn't have much for them to do. But remove them and all the padding, and you're left with what? An episode and a half? The special edition can't remedy the problems at the story's core, but it at least gets rid of the technical irritants, including the bad action scenes.