First broadcast 1 May 2010.

The Doctor (Matt Smith) and his companions are on the run from the Weeping Angels through a forest inside a spaceship – but while the Angels stalk them, something even more dangerous is developing in the heart of the ship.

To start with a little Doctor Who history lesson: writer/producer Steven Moffat originally created the Weeping Angels for a two-part story in Doctor Who‘s third season, “Silence in the Library” and “The Forest of the Dead”. When other writing commitments restricted his availability his two-episode slot was shifted to Helen Raynor for “Daleks in Manhattan” and “Evolution of the Daleks”. A short while later Moffat found enough time to contribute a single episode, and so he co-opted the Angels into their own story “Blink”. The following year, with more time, Moffat finally wrote “Silence in the Library” and replaced the Angels with a new monster called the Vashta Nerada. I’m explaining all this because in many respects “The Time of Angels” and “Flesh and Stone” feel pretty much like what I imagine a Weeping Angels version of “Silence in the Library” and “The Forest of the Dead” would have been like. This episode even has a forest in it.

It is a great, very Doctor Who-esque concept to put a dense forest into the middle of a starship, drawing in light from passing stars and providing the ship with oxygen. Other science fiction texts have tried something similar of course, but here they’ve dropped in an actual forest. It’s another fairy tale touch in a season that’s rapidly filling with similar fairy tale moments.

Amy (Karen Gillan) continues to have a terrifying experience. Last episode she looked into the eyes of an Angel – because if she didn’t it would sneak up and murder her. Now she has a tiny copy of an Angel growing inside her mind. To stop it from growing and killing her she must keep her eyes shut. She is also stuck in a forest surrounded by Angels, who can only be prevented from killing her if she opens her eyes – an act that will now kill her. It is the sort of high stakes, high tension dilemma that represents Moffat’s horror at its best. The Doctor’s solution – for Amy to pretend she can see while keeping her eyes shut – feels like a bit of a cheat, but in the context of the scenes and with such excellently tense direction by Adam Smith, it is a cheat I am willing to accept.

There is some very clever plotting going on in this episode that is easy to overlook. The cliffhanger from “The Time of Angels” is resolved by the Doctor taking advantage of the Byzantium’s artificial gravity. It initially feels like a clever bit of sci-fi nonsense, but of course it also introduces the idea that the ship’s internal gravity is failing. When that failing gravity helps solve this episode’s climax, it doesn’t feel like a cheat because it has already been subtly foreshadowed.

That said, something very odd does happen in the episode’s second half; the climax of a two-part serial is shattered to pieces by the arrival of an overriding season-long story arc. “The Eleventh Hour” introduced the idea of cracks appearing all through time and space, and the phrase that “silence must fall”. We saw the crack again in “The Beast Below” and “Victory of the Daleks”, and the latter episode had the Doctor surmising that pieces of history – like the Dalek crisis of Season 4 – were being eaten up and removed from existence by the cracks. Now another crack appears, bigger and hungrier than ever. It doesn’t just look ominous this time – it chews up and eliminates the entire climax of the story. The Weeping Angels aren’t defeated so much as arbitrarily removed. The same goes for almost the entire squadron of clerics aiding the Doctor, Amy and River.

You could argue it is a ‘deus ex machina’ ending; that’s a theatrical term, meaning “god from the machine” and signifies the sudden and arbitrary arrival of a conclusion without warning. It used to happen a lot in classical Greek theatre where things would reach a crisis point and Zeus would suddenly pop up to make everything okay. Now the crack in time in “Flesh and Stone” is an interesting example of that, because in the context of a self-contained two-episode serial it really does come flying out of the blue. In the context of a 13-episode story arc, however, it is a logical and welcome progression of a growing crisis for the Doctor. What is a viewer to do?

Part of why it works as well as it does is because one terror has been replaced by an even greater one. The crack generates great moments of horror, as one by one Father Octavian’s soldiers wander off to investigate a glowing light in the distance, only to silently cease to exist once they’re out of sight. Octavian’s own death is equally horrific, but in a different way. Trapped in a headlock by an advancing Angel, he lives only for as long as the Doctor doesn’t avert his eyes. It’s a nice moment, and both Iain Glen and Matt Smith play it very well.

The episode’s epilogue is rather uncomfortable. The Doctor returns Amy to her home on the night before her wedding, and she immediately tries to have sex with him. It feels instinctively wrong. The Doctor is visibly distressed, and Amy doesn’t seem willing to take no for an answer. She’s about to get married and seems intent on cheating with her fiancée, which reflects poorly on her character and makes her seem slightly unlikeable. Most of all it’s pretty much the most overt intrusion of sexual themes into the series yet. Through the preceding five years under Russell T Davies, Doctor Who remained at heart a program for children, albeit one that adults could freely enjoy as well. With scenes like these Moffat is pushing the series into not an adult phase per se, but certainly a less child-friendly one. The scene does advance the season’s overall arc – the universe is due to be destroyed on Amy and Rory’s wedding day – but it feels tonally misjudged.

Despite that last-minute failing “Flesh and Stone” is a great and wonderfully inventive episode. This is the exact kind of Doctor Who I adore: fast, panicky, frightening, and wildly inventive.