Gordon was on the scene of an abandoned factory where dozens of hideously deformed bodies had been found. He knew this would be a "freak" killer, like the Red Hood. Batman feared it was just the beginning.
A newscaster, reporting on the reopening of Arkham Asylum, began coughing and died - on camera - with a huge smile on her face. A clown dressed in purple addressed her audience. He threatened to kill everyone in Gotham, and said Henry Claridge would be his next victim. Gordon met Batman at the Arkham scene. The clown had killed the entire TV crew and made off in their van.
Commissioner Grogan held a press conference on the situation, assuring people that the madman would quickly be in custody. Even with Gordon and SWAT on site to protect him, Claridge died at midnight by what appeared to be a time released poison. In his last moments, he laughed maniacally, got pale, and his hair turned green, just like the reporter. Batman went after some escaped mental patients nearby. Gordon got word from the only surviving witness: "Joker" burst into the hospital with C4, machine-gunned everyone in sight, then handed off weapons to the patients in the mental ward.
The next morning, while Bruce was analyzing blood samples of the dead reporter and Claridge, Joker made another broadcast. He fingered his next victim: Jay W. Wilde. Gordon and his men were at Wilde's that night; Batman waited outside. Joker cut the power and caused a distraction with a helicopter. He and Batman fought, but the madman escaped. Wilde was found dead in the aftermath.
Going on a lead that Claridge and Wilde were investors in Ace Chemical Processing, Bruce disguised himself as a reporter and checked it out. An employee who'd been splashed with some of the chemicals had white scarring on his face. He told of another who's arm hair was permanently dyed green when he got some on him. Batman wondered if Red Hood and Joker were the same, but Red Hood appeared to be different people, and they never killed anyone.
Joker broadcast again: Judge Thomas Lake and Bruce Wayne would be his next victims.
Wayne, under police surveillance, poisoned himself. His "team of doctors" (Alfred) dosed him with the antidote in the ambulance. When he awakened, they were under attack by Joker's men. Batman radioed Gordon to have the city shut down the water supply - Joker planned to poison the reservoir. Batman got to him before he did the deed. Joker was captured and placed in Arkham.
Wayne survived and rebuilt the viaduct Batman destroyed to stop the poison. Gordon showed Batman his new spotlight.