In an empty park during fall, the title character, Geri (voiced by Bob Peterson), is an elderly man who plays a game of chess against himself, "becoming" each of the players in turn by moving to the other side of the chessboard, where he changes his personality and either puts on or takes off his glasses to show this change.
As the game progresses, it seems as though there are two people playing; at one point, the hands of both "opponents" are seen within the frame. Geri's aggressive alter ego soon gains the upper hand over Geri, capturing every one of his pieces except for the king and the queen. Just one false move on the king and the queen is captured and he can't move his king, putting him in check.
However, Geri outsmarts himself by faking a heart attack to distract himself and spinning the board around, knocking over the pieces. While his alternate self is still distracted, Geri checkmates what is now his opponent's king.
Finding that he is now the one who is losing and realizing what has happened, Geri begrudgingly resigns the game and hands over a set of dentures as the prize. Geri then puts them into his mouth, chuckling and basking in his victory as he sits by himself, while the camera pulls back to reveal him alone at the chessboard.