Amy and Rory now live in a small and calm village and Amy is pregnant. One day the Doctor visits them by accident and they show him around. When they fall asleep on a bench, they are suddenly back in the Tardis and find out that they all had the same dream. Something is wrong in the Tardis but before they can find out what, they are back in the village. They flip back and forth between the Tardis and they don't know what is real anymore. Suddenly there is someone else in the Tardis who call himself the Dream Lord. He tells them that they have to decide which world is the real one or they die. In the Tardis, they are falling into a cold sun and start to freeze to death and in the village they are attacked by the old people who are aliens. It's up to Amy to choose which world is the dream and when Rory dies in the village, she knows how to decide. Are they in the real world now?
This is a great episode for the relationship between Amy, Rory and the Doctor. Here, Amy has to decide whom her heart belongs to and in the end she chooses Rory. That doesn't mean she won't flirt with the Doctor anymore but now we know who her true love is. The story is quite interesting because the Doctor and his companions have to find out what the real world is and what the dream and that is not an easy thing to decide. When you see that the old people in the village are aliens, that's a bit strange but it fits into the world of Doctor Who. This eye thing in their mouths is just a bit gross. I think the explanation in the end, that the Dream Lord was no one else as the Doctor is interesting. It has to be some of his darker parts which he normally prevents to bubble up. In this episode we can see that there is more to the Doctor than the eye can see, especially from his dark side which he doesn't show often.