The Doctor is under the console, fixing the TARDIS. Amy tries to get his attention but he is too busy. She is annoyed that Rory is helping the Doctor install thermo-couplers. At first she thinks that he is helping the Doctor fly the TARDIS. Rory says that Amy couldn't fly the TARDIS and that she cheated on her driving test by wearing a short skirt. At that point the TARDIS goes dead. Rory apologises for dropping a thermo-coupler. Amy says it is her fault: Rory was looking up her skirt through the TARDIS's glass floor. She is wearing the skirt from the driving test. The Doctor lands the TARDIS in the nearest safe place. Unfortunately, it has materialised inside itself near the door. The Doctor walks into the TARDIS, coming back into the control room through the outside doors. Rory thinks this is cool but the Doctor tells him they have caused a space loop: they are trapped inside the TARDIS forever. Another Amy walks through the TARDIS doors telling them that this is where it gets complicated.

The new Amy explains that she stepped into the TARDIS which is now in the future entered the TARDIS a few seconds into her past. The first Amy asks how she knows this but the new Amy says that this is what she has just been told by herself. She adds that she entered the TARDIS after slapping Rory. Rory asks why he was slapped. The Doctor tells them the timeline must be followed or they would end up with two Amys: Rory's face brightens and Amy slaps him. The Doctor tries to get Amy into the TARDIS but she stops to flirt with herself. No sooner has she gone through the door than a second Amy and a second Rory enter through the main doors. They tell the Doctor that he told them to go into the TARDIS. He tells the first couple to go in and the new couple to stay where they are. He then tries to set off a controlled temporal implosion to resolve the problem but he doesn't know which lever to pull. A second Doctor appears through the door and tells him to pull "the wibbly lever". The Doctor pulls it and runs into the TARDIS which dematerialises.

Everything is back to normal. The Doctor tells Amy to put some trousers on to prevent this happening again.