The Ace Chemical Processing Plant is a chemical plant in the Gotham City, located next to the Monarch Playing Card Company. It is often used as a hideout for the Joker and, in most Batman continuities, the place of the Clown Prince of Crime's origin.

Fictional HistoryEdit

Ace Chemical is based in Gotham City. The plant is connected to Kane Chemicals, a company owned by the parents of Martha Wayne, which was then sold to Apex Chemicals, which then in turn became Ace Chemicals.

On the night of a heist of Ace Chemicals planned by the Red Hood gang, Batman learns of the gang's plan and intercepts them at the chemical plant. Batman confronts the gang's leader, the Red Hood, who is then accidentally knocked in a vat of chemicals by Batman after the heist fails. The Red Hood survives, but exposure to the chemicals leaves him with green hair, chalk white skin, and red lips. The Red Hood's disfigurement drives him insane, and he becomes the Joker.

Over the years, the Joker has revisited Ace Chemicals several times, and on occasion has even used it as a temporary hideout. Notable examples include Death of the Family, where Joker and Harley Quinn lure Batman to the Plant to repeat the "accident" that transformed the Red Hood into the Joker.