Ever since the monorail was built, many subway lines and stations were closed. One of these had become the haven for a small colony of the homeless. With all of the other issues plaguing Gotham, they had been left alone by the city government until they could figure out a better way to profit from them, with only charities coming through to offer help.
They also served as a barrier of pity and grime for The Joker to store one of his armories in the deeper tunnels.
Joker didn't need to say anything when he came striding through. They parted in his wake. They feared him, and wouldn't dare betray his stash. And all it cost him was one tank of gasoline and a man known only as Patches. Pieces of the jacket that gave him his moniker hung over them as a reminder.
As he neared the end of the colony, a dozen stood and joined him while putting on red hoods. One unlocked the door to a maintenance station and held the door.
"Change of plans boys." Joker started once the door was locked. "The Purple Dragon Prank fizzled out when those dunces told too many people what they were up to, and their tiger mom foiled the whole thing. But no matter." He went to the lockers where he stored the weapons and took out another two canisters of Joker Venom to store in his jacket. "I showed that kitty Gotham is
my jungle. Soon enough they'll all know. Clear this place."
"You got it, boss." Said the goons and they started loading themselves up with weapons and ammo while Joker opened one locker and threw out four duffle bags that had been stacked inside. He unzipped one to reveal bundles of crisp bills.
"Those lovely little guns are causing sweet chaos out there." He took out a bundle of 100's and flipped through them, inhaling the smell and grinning. "But we can ramp it up even more." He dropped the bundle back in and zipped the bag then flung it at the nearest goon, who seemed beside himself. "Take a bag and spread the wealth however wherever you can. It's all legal tender. Once you're done, wait for me at Station 18." The goons almost couldn't believe it and were scrambling over each other to get a bag.
They didn't even question why he was suddenly so generous. Guns and cash, for free? It was a criminal's Christmas for them. When the goons had gone with their orders and prizes, Joker pulled one last bag out of another locker and brought it out to the colony. They regarded him with apprehensive eyes as he opened the bag.
"Ladies and gents, you've all been just wonderful hosts keeping one of my nest eggs warm. And as your reward..." He unzipped the bag and as he walked, broke the bands on the bills to spread them everywhere. The tunnel became a mad scramble as everyone jumped and clawed at the air to grab the bills fluttering down. "…. take it all! Buy a good meal! Buy a girl! Buy a boy! I don't care! Just spend spend spend!" He yelled and laughed as he continued to shower the colony with money until he held an empty bag. He watched the colony crawl over each other and start to disperse.
"Wait until they get the punchline…hehehehahahahaHAAAHAHAHA!" He cackled as he threw on some discarded rag clothing and a scarf to hide his face. He slipped out with the rest into the night. As he walked the streets with a fake limp, he saw that many of the homeless were wasting no time. A diner was quickly filling up with them. So was a convenience store.
Ignorant that every bill they passed, was passing a slow death. A special little toxin nicked from Poison Ivy that was odorless to humans and most animals. Every bill had been doused in the toxin then dried. His test subjects had died in agony hours after handling a bill for more than a minute. Even worse if they put the bill up to their nose to sniff it. He was immune to it of course. It wasn't as toxic as Joker Venom after all, just far subtler.
Now that his gift to Gotham was out, Joker limped his way to the Iceberg Lounge. He could see from blocks away it was on fire, and he desperately wanted to see it.