Mayor Hill is giving a speech at a construction site, saying the new block of apartments being built will herald a new, safer
Gotham City. The speech is rudely interrupted by a pair of criminals who crash their getaway car and then open fire on the police pursuing them.
Batman appears and takes them down. Rising from the podium he ducked under, Hill resumes the thread of his speech, railing against men who act outside the law, including Batman, whom Hill compares him to other criminals like the
Joker.
The Joker happens to be watching this in his hideout, and is outraged at the comparison. He gets an idea for revenge when Hill's next statement promises to make the city "as safe as [his] own mansion."
That weekend, the mansion is the site of a birthday party for the mayor's son,
Jordan. The party is more a political media event than an actual celebration, and Jordan feels overlooked and unloved. Practicing magic tricks alone in his room, he is mad when his father barges in and demands that he come out and greet the blue bloods.
However, Jordan perks up when the party's entertainment arrives, magician and jokester "
Jekko the Clown". Jordan is awed by Jekko's act, and asks how he can become a magician like him. Jekko laughs and says the first necessary step is to run away, find a great magician, and then steal his act. Jordan asks Jekko if he could show more magician tricks to him, to which Jekko agrees and begins to show him something special by telling him that he is saving the best for last. Then Mayor Hill insists that Jordan has to leave the clown and come back to greet the new arrivals, including Bruce Wayne. Fed up, Jordan accuses his dad for making him feel unloved and runs back inside.
For his parting gift, Jekko plants a large sparkler candle on top of the birthday cake (in reality, a large stick of dynamite). As he leaves the Mayor, he lets out one of his trademark laughs. Sensing something familiar, Bruce looks around and sees the candle, where he notices the Joker's face on it, realizing what is about to happen. Pushing his way through the crowd, he pretends to stumble with the large present he's carrying, knocking the cake into the pool, where the bomb detonates harmlessly underwater.
Hill calls the
police, who have found a man claiming to be the real Jekko tied up down the road from the mansion. As Hill demands answers, Bruce realizes that Jordan is missing and then he asks Hill where Jordan is. It turns out he has run away by stowing himself away inside Jekko's van. Hill becomes saddened about Jordan's disappearance and expresses regret at not paying his son's happiness more attention. Reviewing a home video of the birthday party, Bruce notices "Jekko" mention the name of his mentor, the "Great Prosciutto", once a performer at the amusement park. This, combined with Jekko's laugh and the dynamite he left, confirms Bruce's suspicion that Jekko was the Joker in disguise, and now knows where to find Jordan.
The Joker returns to his hideout, an abandoned amusement park. He starts to remove his makeup, but Jordan appears, saying he has run away and followed "Jekko's" advice and wants to be a magician like him. The Joker is initially enraged at having his hideout invaded, but laughs it off and says he's been thinking about a protégé to which Jordan agrees with. As his first "lesson", Joker tries to teach Jordan to swallow a trick sword, giving him a demonstration, although it is apparent that the Joker hopes Jordan will cut himself fatally. The security alarm goes off and the Joker sees Batman entering the park on the surveillance system. He proposes that he and Jordan play a little joke on Batman, and Jordan, remembering his father's negative opinion on Batman and not wanting to disappoint his new mentor, agrees.
Jordan appears outside an empty theatre to lure Batman in, and runs inside when Batman chases after him. When he's inside, the Joker throws a whole deck of his razor-sharp playing cards at him and misses. Batman gives chase, but the Joker throws an exploding gas card that knocks Batman out. The Joker drops a quarter into a fortune-telling machine, which drops a card predicting Batman's fate. The Joker reads it and laughs.
When Batman awakens, he is upside down in a tank rapidly filling with water, bound by a straitjacket and shackles. Jordan is nervous, but the Joker tells him to watch the "show". Jordan applauds when Batman manages to get free of the straitjacket, but then realizes that Batman really is drowning. He grabs an axe and strikes the side of the tank, but the Joker plucks the axe away before he can strike again, and removes his Jekko mask to reveal who he is. Horrified, Jordan grabs a seltzer hose and sprays the Joker in the face, distracting him long enough to run out. As the Joker chases after him, Batman pushes with his legs on the crack Jordan made, and manages to shatter the tank. Recovering his breath, he grabs his utility belt and goes after the Joker.
As the Joker searches the amusement park for Jordan, Batman runs to the park's control room and throws the power switches, turning on the park's lights and attractions, to distract the Joker and illuminate the area.
The Joker catches up with Jordan, hiding on one of the roller coasters, just as Batman sees them. Joker starts one of the coasters and he and Jordan roll away on it. Batman jumps on the second as it starts, slightly behind the first.
As the cars speed around the track, the Joker throws Kewpie doll-shaped grenades at Batman's coaster. One of them lands right in the seat of the lead car, and the coaster derails in the explosion, causing a massive hole in the track. However, Batman has managed to jump onto the rear of Joker's coaster while the Joker lunges into the back. As they wrestle, Joker tries to squirt Batman with his boutonniere, but Batman ducks and kicks him off the coaster, although he lands safely in the water.
Looking ahead, he sees the coaster is heading for the break in the track caused by the explosion, while Jordan is still in the lead car. Batman yells for Jordan to take his hand. Jordan hesitates for a moment, then reaches, and Batman swings them both away just before the coaster goes off the rails and crashes. Batman takes Jordan back home.
At the mayoral mansion, Hill is sadly toying with his son's magic tricks, when Jordan appears and runs into his father's arms. Having learned a lesson about how truly important his son is than doing a political media event, Hill gives him "the best birthday hug" he's ever had. Over his father's shoulder, Jordan sees Batman smile and give him a thumbs-up to tell him he did the right thing. Jordan smiles back and returns it.
clown..
