Lucy thinks that she is the arm-wrestling champion of the neighborhood. Charlie Brown challenges Lucy to beat Snoopy as his "Masked Marvel" alter ego. During a really tough arm-wrestling competition, Snoopy kisses Lucy on the nose. Lucy declares that Snoopy made an unfair move by doing so. That makes Snoopy's victory invalid and means that Lucy is still the arm-wrestling champion. The short ends with Charlie Brown saying, "You let us down, 'Masked Marvel'"