A/N: I've wanted to do an 11/Amy body switch since my last story, but I haven't been able to do one until now since I have been preoccupied with my other stories. Anyway, on with the story! Enjoy!
The Doctor was running around the console room, trying to stop the TARDIS from phasing out of existence, while Amy was in the shower. But then, something unexpected happened. River Song, now better known to the Doctor, Amy and Rory as Melody Pond, materialised in the console room, right next to the Doctor. "Hello, sweetie." she greeted in her normal manner. "River, not exactly the time now, if you haven't noticed yet!" the Doctor shouted over the noise of the engines groaning. But before he could complain, he realised that the TARDIS had calmed down, and looked through the glass column of the console, and saw that River was controlling the TARDIS with ease. "Thanks, River, that help was really needed, I wouldn't have been able to control it on my own, and that would have spelt the end of me and Amy." said the Doctor gratefully. "No problem, sweetie." replied River.
"DOCTOR!" came a very distant voice from beyond the TARDIS control room. The Doctor ran down the TARDIS corridors and came to a stop outside of the kitchen. He opened the door, and saw Amy standing there with a small green alien in her hand. "Amy, where did you find that?" That thing spits out poisonous slime. Pass it to me." said the Doctor, cautiously. He pulled out an empty pickle jar, and Amy carefully put the alien inside. The Doctor quickly sealed the lid, and walked out of the kitchen, Amy following suite.
When they reached the control room, the Doctor pulled a lever that would unlock the doors and put the TARDIS on autopilot. But just as the Doctor started walking away, the alien let out a very high pitch squeal. Luckily, the jar didn't smash since it was made out of a special type of carbon glass, but the Doctor did end up stumbling into a whole variety of levers. The TARDIS started to blare out a warning siren, and the Doctor quickly chucked the alien out of the TARDIS and ran back to the console to see what had happened, but the Doctor and Amy were the only ones in the control room, and they needed River urgently. Where was Rory when they needed him? The TARDIS started to shake violently, and the console sent out a shockwave that hit the Doctor and Amy, which knocked them out. The shockwave shook the whole TARDIS, and River and Rory got knocked out by the shockwave as well.
The Doctor was the first to awake. He jumped up quickly after hearing the TARDIS alarm still, and it took him moments to realise that he had two lumps on his chest, where there shouldn't be any there at all. He took a proper look down, and realised that he was also a girl. Had he regenerated? He turned to look for Amy and saw his body lying on the floor. "Am I dead?" he thought out loud, and realised what he had said, or rather, how he had said it. He looked in the screen at his reflection, and saw Amy staring back at him. "I'm Amy." he said, and then, a smirk grew on his face. But before he could do anything, he heard Rory's voice approaching the top of the stairs. "Doct... oh, hi Amy! Listen, I need to explain something. I'm in my father's body! It's me, River!" said 'Rory' rather quickly. The Doctor stood there, dumbfounded. "River, it's me, the Doctor!" exclaimed the Doctor. This was not turning out very well at all.