Quagmire's dad comes to town and Peter and Joe think he's gay (he is very flamboyant.) They tell Quagmire his suspicions and Quagmire is in denial at first but then he questions his dad and his dad tells him that he's not gay..but he is a woman trapped in a man's body. The episode follows the surgery and then Brian (who has been away at a conference the whole time) coming back and meeting Quagmire's dad (who is now a woman) and sleeping with him/her