Spoiler Level: High
I feel like I've only seen half of the episode and therefore can't fairly review it, which is interesting because that doesn't normally happen to me with the Doctor Who two-parters. More on that later.
The TARDIS arrives on Earth in the future, at a factory that makes dopplegangers out of synthetic flesh. Since the synthetic flesh is made from acid, it's dangerous to work with and the staff all use "Gangers" of themselves to do the job. But once a solar storm hits the factory, the Gangers come to life on their own. They're confused and frightened, and the original people they're based on are just as frightened of them. The Doctor recognizes them to be real people in their own right, duplicates of the originals right down to every last memory but just as deserving of life as their originals. And most of the originals, while a bit uncomfortable with this, are open to exploring what to do about it until their leader kills her Ganger, leading to the drawing of battlelines. Oh, and due to the Doctor's trying to figure out just what the synthetic flesh was, a batch of it has now duplicated itself on the Doctor. Cue the "time-vortex scream" sound and roll credits.
Now normally at this point I feel like I've been given a lot of questions and it makes me want to speculate. But in this case, I kind of feel like things progressed along inevitable lines, so while I'm entertained, I don't really have a lot of curiosity on where the story is going to go. Not so much predictable as just... inevitable.
The Doctor's trying to reconcile the Gangers and their originals together was great; it's so typically optimistic of him. Now in the old classic Who days the duplicates probably would have automatically been out to kill their originals. When one of the originals expressed this concern, the Doctor asks him, "Are you prone to violence?" "No," he replies. "Then what makes you think your Ganger would be?" And it's a great point. And it made me think what I'd do in that situation. I think I'd actually like to sit down and have a talk with myself! Would it be enlightening? Would it be annoying? Would it be like finding a long-lost twin, or would getting to see all the little imperfections that my mind's eye leaves out be too disturbing? But no one seems to really look at this way; the Doctor is more concerned about preserving new life, and the originals are more creeped out by having duplicates of themselves. It's never stated outright, but it's obvious they feel threatened that they will lose their individuality to what they consider nothing more than a technological glitch.
So the leader turning on her Ganger and killing her ("That is so like me," she says before she dies) feels inevitable; the complete breakdown of trust between the two sides becomes inevitable; and even the Ganger of the Doctor showing up at the end felt inevitable. I feel like the second half's outcome is going to be inevitable as well-- both sides fighting each other until everyone is lost, a tragedy tale of humanity's inability to accept itself.
Hopefully I'm wrong; it would be nice to be surprised. And that's why I feel like it's unfair to review this story at this point. The intention may very well be to make me feel like it's inevitable to deliberately set up for a surprise at the end. I won't know until I see it.
Speaking of which, I'll have to wait an extra week to see it, since BBC America is skipping Doctor Who next week because it's Memorial Day weekend. Which really bugs me, because (a) it airs on Saturday and Memorial Day isn't until Monday; do that many people really travel that far for their backyard barbecues? And (b) we live in the age of Tivo. Okay, I suppose it might impact actual live ratings but it's not like it's going to make it harder for anyone to catch it. And (c), by losing the same-day airing (especially in the middle of a two-parter!) they're going to lose more people to illegal downloads. At least we'll only be behind the UK for two episodes and not for eight due to the show taking a summer break this year, but for some people that one-week delay is just too much They've proven that same-day airings boosts the ratings, so I presume it also cuts down on downloading; I guess this will reinforce that one way or the other. A nice compromise would be to offer the legal download on iTunes and Amazon at the same time as it airs in the UK, and then just air the episode a week later on BBC America, but I sincerely doubt they'll do that.
And lastly, I do rather like the feel of the story, as it feels very much like a classic series story, and it being shot in a castle helps that. I also like Rory getting a moment to shine with Jenny; someone's appreciating him from the get go, and it's obviously boosting his ego. Looking forward to the (perhaps not so inevitable?) conclusion.