Joker is already a known criminal in this story. He goes on a killing and robbing spree, murdering 2 men to steal their jewels, a judge who had previously sentenced him to prison, and shooting a crime lord who was angry with him for stealing the jewels first (it is unknown if he killed the crime lord, however). He uses his joker venom to kill as well as a gas to paralyze the police. When he kidnaps Robin, Batman is able to track Robin down to his hideout and save him. Robin had overheard the next item Joker planned on stealing and they were able to stop and capture him before he could kill again. The Joker is sent back to prison.