"A Weeping Angel, Amy, is the deadliest, most powerful, most malevolent lifeform evolution has ever produced, and one is trapped inside that wreckage. And I'm supposed to climb in with a screwdriver and a torch, and assuming I survive the radiation -- and the whole ship doesn't blow up in my face -- do something clever which I haven't thought of yet. That's my day. That's what I'm up to. Any questions?" Just one: Does every fucking episode need this exact same speech? We get it, the stakes are high. "Is River Song your wife?" He sighs and looks away, but she's loving it: "Because she's someone from your future, and the way she talks to you, I've never seen anyone do that. She's kinda like, you know, Heel, boy! She's Mrs. Doctor from the future, isn't she? Is she gonna be your wife one day?" He admits it, and she's shocked. "You're right. I am definitely Mr. Grumpy Face today." River calls his name, and he's hangdog for a moment. They head into one of the Church barracks, I think, as the Doctor explains Octavian: "He's their Bishop, they're his clerics. It's the 51st Century, the Church has moved on."
River's rigged up a film loop from the cameras inside the vault, four seconds, which the Doctor identifies as an Angel, "hands covering its face," which he only says as a clunky way of telling us to watch its hands and its face. He recalls the time with Sally, but notes that in that case they were "scavengers, barely surviving." (Also, they were cool and interesting and didn't move when we the viewer were looking at them, and they killed you by sending you back through time instead of just being super mean. The regular ones we're meeting today have very little in common with them.)
We run through the whole thing about the Angels, River being sweet with Amy as she asks Excellent Questions about how they're not really "just" statues unless you're looking at them, and we learn that this particular one on the video loop is a dormant collector's item, pulled from the ruins of Razbahan at the end of the last century. "There's a difference between dormant and patient," the Doctor says scarily, and then explains the central plot hole in this story: "It's a quantum lock. In the sight of any living creature, the Angels literally cease to exist. They're just stone."