At Woodrow Roosevelt High School, a vending machine gives out money. Dick Grayson is there to witness it. Batman learns the vending machines are operated by a company bought by the Joker after being released from prison. The Joker and his gang are aided by Susie, a cheerleader at the school. In the course of their investigation, Batman and Robin are captured and placed in electric chairs. If a "one armed bandit" comes up the wrong way, they'll be electrocuted.

A power failure prevents Batman and Robin from being electrocuted. Meanwhile, a recording Batman made confirms that cheerleader Susie is one of the Joker's confederates. Robin, in his Dick Grayson identity, attempts to infiltrate the gang. Meanwhile, the Joker's main plot is finally revealed. Members of the high school basketball team receive answers to final exams from the rigged vending machines. The Joker appears, claiming to be a concerned citizen. The team's starters will be suspended as the Joker bets big money on the team's next opponent. Batman, however, has other ideas.