As the Justice League tries to protect the United Nations from Gorilla Grodd gorilla army, Mister Mxyzptlk pops up from the fifth dimension and thinks it would be great fun to....

Mr. Mxyzptlk decides to create some mischief by granting Shazam's well-meaning Uncle Dudley with superpowers bigger than anyone in the league.

Mr. Mxyzptlk shows Supergirl and Superman that their innate goodness might not be so pure when he takes them to a parallel world where their counterparts are impossibly aggressive and spoiled.