The Fantastic Four study a radiated meteor. The Molecule Man appears and threatens the public. After the Fantastic Four tastes some of his power, he leaves to undergo his ruling the world. Reed has developed a weapon he thinks will defeat the Molecule Man. The weapon works, but the Molecule Man gets away. The Fantastic Four continue their pursuit. The plan to stop the Molecule Man is tricky. They manage to reverse the Molecule Man's form with a fragment of the meteor.