HITLER: He was going to kill me...
RORY: Shut up, Hitler!
DOCTOR: Rory, take Hitler and put him in that cupboard over there.
Like, seriously, spoilers. Let's Kill Hitler directly continues a story seeded in 2008 and threaded through three seasons. Every River Song episode leads to this one. And it's impossible to talk about this episode without referring to its many, many revelations.
But it's a good one. Not perfect, and yet another episode that should have been doubled in length, but fast, funny, clever, compelling, and, for the most part, satisfying.