This is possibly the best episode of Season Four. It features a great story and one of the most classic moments in the show's history. When Jerry meets a man who's son lives in a bubble, the father and his friends get him to visit the bubble boy in Upstate New York. Well, because of some crazy circumstances, he's not able to make it, George makes it instead.
George and Susan make it their and encounter the bubble boy, one of the most sarcastic and best one time (excluding "The Finale") appearances in the show's history. I won't go into detail of what happens but it is classic. Also, Kramer, trying to reach the others at the cabin accidently burns down Susan's father's cabin.