Rory and Amy get the Doctor’s attention by making crop circles in their hometown. When he shows up, he’s met not only by the Ponds but also by their friend Mels. She’s sassy and wears beaded braids and has been best buds with Amy and Rory since childhood. Having grown up listening to Amy’s stories, Mels seems quite cross about the Doctor, a man she’s come to blame for all history’s greatest tragedies. She forces her way onto the TARDIS at gunpoint and then suggests they all go kill Hitler.
Also out to do away with the Fuehrer is a futuristic crew from some Justice Department. They members have shrunk themselves to control a shape-shifting robot from the inside, and disguised it as some random Nazi. Just as the random Nazi robot is about to kill Hitler, the TARDIS materializes and everything goes to hell. Naturally. The Doctor’s a bit squeamish about inadvertently saving Hitler’s life, so he has Rory just stuff the guy into a cupboard. There he remains for the rest of the episode. Meanwhile, Mels has been fatally injured in the craziness. Except she doesn’t die, because she’s actually Melody Pond and she regenerates into the River Song we’ve come to know and love. Except she doesn’t know who River is at this point. Having been brainwashed by the Silence all her life, she wastes no time in kissing the Doctor with some poisonous lipstick. He’s doomed to die in minutes, with no prospects of regenerating… for some reason.
The Justice Department sets its sights on River, who’s apparently an even bigger target than Hitler thanks to her future killing of the Doctor. Amy and Rory rush off to save her and get shrink-rayed into the shape-shifting robot. The Doctor, although flailing about from his poisoning, is hellbent on saving them and River. He does, of course, but he can’t save himself and soon expires. The Ponds finally tell their childhood friend the truth about River. River, somehow overcoming years of brainwashing, brings the Doctor back to life by using up all her regenerative abilities. It’s all very rushed and very confusing and kind of good in places. I’ll try to sort it out in the Weecap.