This week's Who was entitled "The Rebel Flesh" and was written by Matthew Graham, who is probably best know for being the co-creator of the series "Life on Mars"
The story begins as we're introduced to a crew of workers who are pumping a supposedly valuable (and definitely corrosive) acid from their island outpost to the mainland. When one of the crew falls into said acid and promptly dies with seemingly no pain, we find that same person 2 seconds later saying he should be getting hazard pay for that.
Meanwhile, on the TARDIS. The Doctor is still poring over Amy's will she/won't she ultrasound. Before he can make any headway as to whether or not she's pregnant, the TARDIS gets hit by a solar storm and the crew find themselves in 22nd century Earth to a certain island outpost...
Quickly, we learn that the workers can create and animate dopplegangers of themselves my use of some creepy looking control beds and a bug vat of goopy liquid they call "The Flesh". Once the second wave of the solar storm hits the island and causes The Flesh to animate without the need for control beds, that is where things get really interesting.
This is probably my favorite episode of the season so far, simply because of the palpable tension the episode's situation creates. The reactions of the crew, the Doctor, and the dopplegangers all rang as very true to me. The episode actually reminded me of the classic Twilight Zone episode, "The Monsters Are Due on Maple Street", which is a good thing. The stand out character for this episode for me was Rory. I think that he gets the short end of the stick when compared to Amy or The Doctor, but he is more compassionate that either of them, and his unwavering conviction to help "Jessica" even after she freaked out and clobbered him was the episode's highlight.
Another great thing about this episode in particular is that it's a slow burn that definitely merits a second part. We're introduced to the concepts, given a great set up, The Doctor comes in and does his thing, and everything is about to wrapped up in a nice bow and everyone's happy, and then... well. My only hope is that the next episode doesn't devolve into an US vs. THEM all out war. This show has done that before, and it isn't really one of its strong suits. The final scene, however makes me hope for the best.
This episode also makes one wonder if the existence of easily created beings that look, act, and feel exactly the same as their counterparts gives the writers an "out" for the events of the season's first episode. I'm kind of hoping that it's much more elaborate that than, though. Some other geeky/speculative things to note: I think Rory may be a doppleganger and not know it. Early on in the episode, he touches the wall of the castle/facility and it burns his hand slightly, since you know, there's acid all over the place. Later, we're told the dopplegangers don't have the same type of nerve endings as humans, and as such don't realise pain as quickly, or at all. Later still, we see Rory touching the wall again with no ill effects. The shot seemed to deliberate to me to be a continuity error, but time will tell.
The one mark I have against this episode is not a fault of the episode itself, but that the second part will not be airing stateside until June 4th, due to BBC America delaying the episode due to Memorial Day weekend. This stings for a couple of reasons, the first being that BBCAm had scheduled this series to air the same day on both sides of the pond, changing that due to the fear of lost Memorial Day ratings is short-sighted. People who really want to see the episode when it airs in the UK next week will surely find a way, and the ratings will be lower on BBC America regardless.
At any rate, you should be checking out the show, this episode illuminates the sort of sci-fi I like to see, classic xenophobia that is really about the human condition.