The JLA fights the Royal Flush Gang and their stelleration-powered abilities to a draw, until they play their wild card...Snapper.
The Jack Of Clubs commits a bank robbery. The Hawkman and Hawkgirl are called in to apprehend the Jack Of Clubs. Using the seven of spades, the Jack Of Clubs exposes the Winged Wonders to a special radiation, that creates discord between them. While the Hawkman argues with Hawkgirl, over the best method to apprehend the Jack of Clubs, said villain escapes. The King of Clubs robs the Metropolitan Museum of Art. The Flash arrives to arrest the King Of Clubs. The King Of Clubs hurls five diamonds into the Flash's face, causing the Flash to hallucinate. With the Flash, essentially, blinded, the King Of Clubs escapes.
The Queen of Clubs steals a diamond encrusted cloak right off of Wonder Woman's back. Using the two of spades, the Queen of Clubs halves Wonder Woman's powers. Using the nine of diamonds, the Queen of Clubs compels Wonder Woman to summon a meeting of the Justce League of America, then to travel to the Secret Sanctuary, to attend said meeting. Still under the influence of the radioactive playing cards, the Hawkman argues with everyone over tactics. The Flash is still virtually blind. Wonder Woman is deeply despondent over the loss of her super-powers. The Royal Flush Gang assemble in their secret lair.
Their leader, the Ace Of Clubs, recalls how he discovered "Stelleration", a special radiation that compels behavior based on the astrological meaning of playing cards. The Ace Of Clubs gathered his old boyhood gang together, to form the Royal Flush Gang. Now, the Ace Of Clubs intends to do away with the Justice League of America. The Royal Flush Gang challenges the Justice League of America. The Justice League of America confronts the Royal Flush Gang. Despite his inability to see, the Flash, working with Superman, manages to effectively assault the Royal Flush Gang. The Queen of Clubs defeats Wonder Woman, in hand-to-hand combat.
The Queen of Clubs casually tosses the nine of spades onto Wonder Woman, inducing violent sickness. Just as Superman is about to capture the entire Royal Flush Gang, the Batman attacks him, kicking Superman into the Flash. Due to exposure to the four of diamonds, the Batman feels compelled to betray his teammates. The Batman trips Superman into the Hawkman, knocking the Winged Wonder unconscious. Feeling he has no choice, Superman punches the Batman into unconsciousness. Exposure to the ace of spades deprives Superman of all of his powers. The Royal Flush Gang is victorious. In defeat, the Justice League of America return to the Secret Sanctuary.
Their mascot, Snapper Carr, begins arguing with the Hawkman. Carr, using reverse psychology, manipulates the Hawkman into using Thanagerian science to create Stelleration radiation. Carr is given the power to neutralize Stelleration. Outfitted in a costume sewn by Wonder Woman, Carr becomes the Joker, the one card in the deck that trumps all the others. Carr neutralizes the Stelleration radiation in the Justice League of America, restoring them to normal. By following the trail of Stellaration radiation, the Justice League of America is able to storm the hidden lair of the Royal Flush Gang.
The Justice League of America is exposed to the four of hearts, creating intense jealousy in the team. Carr neutralizes the Stelleration radiation. A giant six of hearts playing card releases poison gas into the room. The Hawkman beats the gas back with his wings. Superman keeps flaming spades from striking his teammates. The Flash saves the team from acid-pouring diamonds. The Batman and Wonder Woman hurl Carr into the Royal Flush Gang, neutralizing their Stelleration-derived powers. The Ace of Clubs is revealed to be Professor Amos Fortune. A portrait of Carr, as the Joker, is hung in the Justice League of America's trophy room.