At night, three people maneuver across one roof in a burglary attempt with a fourth person looking out for any potential problems. Unknown to them, the four burglars are being observed by a mysterious person, who openly talks of admiring their style.
The burglars blow open a safe inside the building but though the sound is muffled, a passing Cyborg hears it and investigates. The burglars throw a smoke bomb and try to run away but wind up in a dead end alley. The mysterious figure, dressed in an odd costume, follows closely behind a pursuing Cyborg and incapacitates the hero with a card that envelops him tightly. The figure, who calls himself Ace, materializes card fliers for the burglars and the five fly away before Cyborg can break free.
Ace and the burglars fly to what Ace calls a House of Cards and Ace tells the burglars they can be the greatest criminal gang of all time with his help. To that end, he uses a machine to change their attire and seconds later, they now resemble King, Queen, Jack and Ten of Clubs figures. Ace leaves abruptly to meet secretly with the group's secret benefactor and gloats that the Super Powers team are unaware the Royal Flush Gang are supported by their two greatest foes.
At the Hall of Justice, Wonder Woman calls in to report seeing four figures dressed as playing cards flying around and Superman and Firestorm leave to help her. The Royal Flush members manage to defeat all three heroes in battle and Ace tells them to return to the House of Cards rather than tangle with the remaining Super Power members that are approaching. The crooks leave but not before Batman secretly hits one of the card fliers with a tracking device.
At the House of Cards, Ace gloats at the sight of the immobilized captured heroes before using a machine to transform them into life-size playing cards. Ten asks who is behind the whole operation and Ace reveals the benefactor is none other than Darkseid and they are on Apokolips.
Outside, Batman, Robin and Cyborg have used the tracking device to find the hideout and after defeating Darkseid's drones, the trio venture inside and Batman deduces that the house disguises a dimensional warp to Apokolips itself. After defeating more drones, the heroes head off even as Darkseid tells the Royal Flush Gang to defeat the rest of the Super Powers team and they can rule two planets at once. Suddenly, Kalibak alerts Darkseid that their enemies are near and after Darkseid leaves to prepare defenses for them, Ten openly wants out of the situation. Moments later, Batman, Robin and Cyborg launch an attack and tie up the Royal Flush Gang and Ace. Batman unmasks Ace and shows his true identity as Joker, which Batman deduced from the lack of a Joker card making up the House of Cards.
A recalcitrant Ten goes to free the transformed heroes with the device used to change them but is struck down by Omega Beams from an angry Darkseid entering the room. Batman, Robin and Cyborg flee the building on card fliers and are pursued by Joker and the Royal Flush Gang on their own fliers. The heroes are captured and brought back to the House of Cards where they, along with the turncoat Ten, are transformed into cards.
Darkseid and Joker send robots off to invade Metropolis and take over the Hall of Justice. Joker notices that Jack is missing and orders the remaining Royal Flush members to find him. Elsewhere in the house, Jack uses the transformation machine to change the heroes back to normal. Batman tries to run off but Jack stops him and reveals that Batman and Jack switched costumes earlier during the fight at Batman's behest to ensure the heroes could win. Firestorm switches costumes for Batman and Jack back to what they should be and the heroes capture the Royal Flush Gang with ease.
The heroes leave the House of Cards with Superman heading off to intercept the robot invaders and Firestorm destroying the House of Cards. Darkseid is angry at how things have turned out and blames Joker for the disaster. Moments later, as Ten is reassured she will be treated better than the other gang members with her change of face, a portal opens above the heroes traveling back to Earth and Joker literally falls into their arms.