When an experimental space voyage goes awry, four people are forever changed by cosmic rays: Reed Richards, inventor and leader of the group gains the ability to stretch his body and takes the name Mr. Fantastic. His girlfriend, Sue Storm, gains the ability to turn invisible and create force fields becoming The Invisible Girl. Her little brother, Johnny Storm, becomes The Human Torch with the ability to control fire, including covering his own body with flame. The pilot Ben Grimm is turned into the super-strong, super-tough Thing. Together they become a team of super-heroes and use their unique powers to foil the evil plans of villains.