Sources state The Joker has been creating a collection of dying gas bombs and that he plans to unleash them around town. The laughing gas tanks have been saved across many heavily guarded warehouses. You'll need to slip through the warehouses and then disarm the bombs. But don't draw too much attention... if The Joker knows you're coming, he'll escape with all the rest of the bombs. Save Gotham City and establish people who you're their actual superhero! Have fun.