Marsha, the Queen of Diamonds, is after the giant diamond that powers the Batcomputer. With her love darts, she puts both Commissioner Gordon and Chief O'Hara under her spell (and into her custody). When the Dynamic Duo show up, they too are injected with her love potion, and Batman must agree to marry Marsha if he ever wants his friends to be returned.

Hoping to obtain the Batcave's bat-diamond, Marsha searches for a new potion to use on the Caped Crusaders. Batman and Robin do some searching of their own and arrive at the criminal's hideout. But after Marsha douses them with her concoctions, the villainess seems to have a unique bargaining chip - two tiny caped toads - with which to gain Commissioner Gordon's help in locating the Batcave.

As a front for his next crime wave, the Penguin forms a motion picture company. He teams up with Marsha, Queen of Diamonds, and gets Batman and Robin to take part in his movie. Marsha attempts to put Batman under her spell with drugged lipstick during the love scene, and filming at the Gotham City Museum of Antiquities turns out to be a good cover for the Penguin to snatch some ancient armor. Moreover, when the fight scene turns out to be all too real, the Dynamic Duo are captured and tied to a giant catapult about to be sprung.

In order to keep a close eye on the Penguin (and hopefully locate the stolen chain mail armor), Batman and Robin rejoin Penguin's movie efforts. The next part of his film is to take place in medieval times. Therefore, Penguin has the Dynamic Duo dress in armor suits, but only to trap them with a giant magnet while he snatches top-secret papers from the Hexagon. Batman and Robin free themselves and follow the villain, but after a losing battle with him, the Penguin has them hauled off as scrap metal to be crushed.

Batman and Robin get back on the Penguin and Marsha, Queen of Diamonds', trail. Several escaped lizards lead them to the villains' hideout, where they find the stolen chain mail suits. Remembering an earlier clue from the Penguin, they head to the federal subtreasury to find that the Penguin, Marsha, and their cronies have broken into a vault containing ten million dollars in gold bullion. The Dynamic Duo shut the vault door on the criminals and try to prepare for every breakout scenario, but the Penguin has a daring plan of escape that no one could have counted on.