The Ace Chemical Processing Plant is the birthplace of the Joker.
The Red Hood gang coerced a nameless comedian into donning the red helmet and conducting a robbery. The gang's intended escape route led them through the Ace Chemical Plant.
On the night of the robbery, the neophyte vigilante known as the Batman learned of the gang's plan and intercepted them at the chemical plant. While trying to escape, the Red Hood fell from a catwalk into a vat of deadly chemicals. He managed to survive, but exposure to the chemicals turned his hair green, and his skin chalk white. It also drove him irrevocably insane. Abandoning his Red Hood identity, the man took to calling himself the Joker.
Over the years, the Joker has revisited Ace Chemicals several times, and on occasion has even used it as a temporary hideout.
- The Ace Chemical Plant has had different names in different continuities and stories.
- Interestingly, the New Earth version of the Ace Chemical Plant is located next to the Monarch Playing Card Company, as depicted in Batman #451.