Tony Zucco has the story on Prankster, and well... he's going to tell it. Turns out that Mayor Cole and his brother headed up a train project years ago, and the Mayor's brother was responsible for the death of the project's Electrical Engineer who had a kid... can you guess who it is!? That's right, the Prankster. So, this whole plan is Prankster getting revenge on his for his father, and turns out, the Mayor never stole any money, it's just important that Prankster convinced the people of Chicago that he did. Prankster's plan was to take out legitimate dirtbags first, so when he called the Mayor out for "stealing" people would believe him, and that they did.
Prankster's endgame is setting off a train full of explosives, enough to level the neighborhood where Cole's project was staged. Prankster then shoves the mayor out into the streets, lighting off a flare to get people's attention. Everyone still believing the mayor is a crook, they come out and start to kick his ass until Dick shows up with Zucco.
Dick gets Zucco to take the mayor away on his bike, while he deals with the Prankster, who attempts to hack his mask again, only to find out that Dick put a killswitch in. With no available tricks left to him, Prankster flees, leaving Dick to deal with the bomb. Not having enough time to disarm it, Dick sends the train out to one of the bridges and has it blow there, away from civilians.
Dick emerges from the water, only to find Prankster trying to strangle him, and he almost does too, until Zucco shoots him a few times. The bullets went clean through, so Prankster is still alive, and Dick leaves the two to the police. And even though Dick got what he wanted with Zucco, he doesn't feel as satisfied as he thought he would.
When Zucco is meeting with a lawyer who represents "old friends" of his, and wants to clear everything up. Zucco is only interested in showing his son that he's taking responsibility for his mistakes, but the lawyer gives him a note from his wife who seems to be filing for divorce. Zucco gets angry and restrained, and once he gets settled down again, the lawyer asks if he'd like to cooperate and beat the charges or go to jail as a martyr for a life he no longer has. The only thing Zucco says is to not call him by his alias of Billy Lester, but Tony Zucco instead.
Meanwhile, that police guy whose name I can't remember is talking to Dick's roommate about how copycats will start showing up and vigilantes are bad, so on and so on. Turns out he's probably the guy who killed all the ones in Chicago in the first place.