World-famous concert pianist Chandell (who leads a second life as the nefarious Fingers) plans to dispose of Bruce Wayne and Richard Grayson and then marry Aunt Harriet Cooper (who will then be the sole surviving heir to The Wayne Fortune), so he can have enough money ($5,000,000!) to pay off his evil twin brother, Harry, who knows Chandell used a piano player during a White House concert which made him famous (he'd hurt his fingers in the piano lid), and has been blackmailing him ever since. As part of his plan to divert any suspicion which just might fall upon him, Chandell arranges for his lethal female assistants - Doe, Rae, and Mimi - to appear at Wayne Manor with their highpitched bagpipes, which they use to put everyone asleep (himself included), and then they ransack the place! Whilst Bruce and Dick are away on vacation, Chandell and Harry plot to strip The Burma Import Compay clean with the aid of his felonious female trio during his concert that evening.

During that concert Chandell strikes an incorrect note, signaling the girls to strike; that note is, of course, discovered by Bruce Wayne, who'd been listening to the concert on his portable radio, and, believing something is stirring, he signals Dick and the two switch identities and return to Gotham City as The Dynamic Duo! Meanwhile, Chandell furthers his plan by playing up to Aunt Harriet. Later, realizing thet The Caped Crusader is on his trail, he assaults himself with a rootbeer bottle and leads them to a trap at twin brother Harry's abandoned Parnassus Music-Roll Co. (located at 99999-79), where they are captured and tied to a conveyor belt which leads directly into a machine that will perforate them into player piano rolls!