An End-Of-The-Year Riddle

I told you about the walrus and me, man. You know that we're as close as can be, man. Well, here's another riddle for you all:

A guy comes to a door that says Singleton's Club. Curious, he opens it and enters the room. Five men are seated around a table. The first has just one arm, the second one leg, the third one ear, and the fourth one eye. The fifth man looks perfectly normal. What's going on?

I will post the answer next year. (Tomorrow.)