Series 6, Episode 8: 'Let's Kill Hitler'
"It was never going to be a gun for you, Doctor. The man of peace who understands every kind of warfare, except, perhaps, the cruellest." Amy and Rory's friend Mels takes the Doctor and his companions hostage in wartime Berlin, before regenerating into the River Song that we know. She assassinates the Doctor, is chased by the Teselecta, and then faced with the decision of sacrificing her remaining regenerations back to bring her future husband back from the dead.
Series 6, Episode 9: 'Night Terrors'
"...And one thing I can tell you, Alex. Monsters are real." A little boy, George, calls for the Doctor's help, as he's scared of monsters. The Doctor must save George's family, and Amy and Rory from a giant doll's house.
Series 6, Episode 10: 'The Girl Who Waited'
"Then there's other people, and you meet them and think, not bad, they're okay. And then you get to know them, and their face just sort of becomes them, like their personality's written all over it. And they just turn into something so beautiful... Rory's the most beautiful man I've ever met." The TARDIS lands on a paradise planet, but Amy enters a different timestream from the others. The Doctor accidentally abandons her again, and is faced with the dilemma of how a young and old version of Amy Pond can coexist in the same universe.
Series 6, Episode 11: 'The God Complex'
"I stole your childhood and now I've led you by the hand to your death. But the worst thing is, I knew. I knew this would happen. This is what always happens. Forget your faith in me. I took you with me because I was vain. Because I wanted to be adored. Look at you. Glorious Pond, the girl who waited for me. I'm not a hero. I really am just a mad man in a box. And it's time we saw each other as we really are. Amy Williams, it's time to stop waiting." The Doctor, Amy and Rory are kidnapped and placed in a 1970s hotel, where a Minotaur stalks the corridors, praying on people's faith. Each character's worst nightmare is concealed behind a door that they try to avoid, and the hotel is later revealed to be an alien spaceship. The Doctor drops Amy and Rory off, as life is getting too dangerous with him.