The adventures of Mermaid Man and Barnacle Boy are being told in a thrilling new motion picture. But as SpongeBob and Patrick soon learn, their heroes are not in the movie. The real Mermaid Man and Barnacle Boy were considered too old, so their filmic counterparts will be two young actors that are nothing like the heroes. SpongeBob is outraged, and he sets out to make his own version of the Mermaid Man and Barnacle Boy movie using the real guys fresh from their retirement home.