Joker's Favor

Joker's Favor is an episode of Batman The Animated Series. It first aired on September 11, 1992. The episode is significant as it features the first ever appearance of The Joker's sidekick and love interest, Harley Quinn (Batman:The animated series). who would go on to be incorporated into the Batman comic book series and eventually become a popular character in her own right.

Plot
Charlie Collins, a nondescript accountant, accidentally runs afoul of the Joker. Pleading for his life, the run-of-the-mill every man promises the Joker anything, if he will only let him go. Joker makes Charlie promise to do him a favor. Two years later, Charlie (who has changed his name to Don and moved to Springdale, Ohio with his wife and son) receives a phone call from the Joker, who wants Charlie to make good on his promise, saying his men are watching the house. He goes to the airport, where Harley Quinn is waiting for him. The favor is as follows: Charlie must open the door for Harley Quinn to bring a cake in which the Joker is hiding so he can infiltrate a testimonial dinner for Commissioner Gordon and plant a bomb. However Charlie, when he tries to leave, finds his hand is glued to the door-handle. At the dinner, the Joker pops out of the cake and Harley sets off the tear gas, immobilizing everyone in the room except her and Charlie, who are both wearing gas masks. The Joker steps out, attaches the bomb to the Commissioner's chest. Fortunately, Charlie had set off a makeshift Batsignal prior to this attack and Batman arrives just in time to get rid of the bomb. A small fight ensues between Batman, his goons and Harley before he faces off with the Joker, who tries to set off another bomb. Batman is able to throw the bomb underground before it detonates, destroying his car. Batman subdues Harley and the two henchmen, but Joker escapes in the commotion, only to bump into Charlie in an alleyway. Charlie produces a bomb of his own, and threatens to blow them both up to protect his family. Batman arrives just in time, and tells Charlie to stop, but he says if the Joker is jailed he'll just escape. Terrified, the Joker, thinking Charley is no fun anymore, gives Charlie all the information he has on him to stop him. Charlie insists and throws the bomb at the Joker who hides behind Batman. However, the bomb turns out to be a fake gag. The scene ends with Charlie saying "Gotcha!". Batman laughs and tells Charlie to go home.