When Carl Met George

George and the Missing Puzzle Piece (also known as When Carl Met George) is the first half of the 6th episode of Season 13. It first aired on April 5, 2010.

Synopsis
In this episode, George tells the story of how he met his friend Carl, who has Asperger's Syndrome. At first, George didn't know about Carl's disorder, and George thought Carl acted a bit strange around him, but he wasn't sure why. Later, when George goes to visit him again and brings his dummy Wally, Carl is unexpectedly terrified of it and it is then revealed by Carl's mother that he has Asperger's Syndrome. George later goes to The Brain for advice on what Asperger's Syndrome is, and The Brain tells him all about it. George then understands what Carl is going through, and decides to bring him a book on trains(Carl loves trains) and also gives him the puzzle piece that accidentally fell into his bag the first time they met. The last scene is George in his bedroom, with Carl sitting at his table(just like he was at the beginning of the episode) still going on about his train picture, but then he almost immediately comes back and says to the viewers "It was nice meeting you" and George explains how he taught Carl to say that, and how Carl taught George to understand his behavior.

Trivia

 * This episode is Carl's debut. He would appear again in the episode Buster Spaces Out.
 * This episode got lots of controversy from people saying that Carl's portrayal was unfair, which it is. There are as many people with high-functioning Aspergers as there are low functioning, and Carl's portrayal was unfair to them.
 * This episode is entitled George and the Missing Puzzle Piece, but on On Demand and Netflix it is entitled the original title, When Carl Met George.
 * The Brain is the only other main character besides George to physically appear in this episode. Arthur and Francine do appear, but this was The Brain explaining Asperger's Syndrome to George. The episode has mostly minor characters in it though in the background.
 * Although Carl's mother is an Aardvark, Carl is a Rabbit. Carl is a mixed family. Carl must be adopted by a aardvark father or have a rabbit father.