WARNING: The following article contains spoilers for this week's episode of Gotham, "13 Stitches," which aired Thursday on Fox.
Gotham may chronicle of the origins of Bruce Wayne and his greatest allies and enemies, but it doesn't adhere to any single version of Batman. Rather than adapt particular comic books, the Fox drama draws from an array of sources, from Christopher Nolan's Dark Knight Trilogy to Batman: The Animated Series to the Arkham video games. In any given episode, viewers may be able to find a clever nod to another depiction of the Caped Crusader, whether it's Jerome Valeska's band playing the Batman '66 theme song or Jeremiah covering his white skin with flesh-tone makeup in an homage to Jack Nicholson's Joker.
Now, in this week's episode, "Ace Chemicals," fans can find another Easter egg, for Tim Burton's Batman. The nod comes when Leslie Thompkins and Jim Gordon sneak into Ace Chemicals and observe a legion of mind-controlled workers manufacturing Jeremiah's chemical weapon. Viewers may notice a clever sign on the side of a vat containing green chemicals.
While the lighting is dark and the plate on the vat's side can only be seen briefly, it appears to read, "Ace Chemicals 1989." Of course, fans of Burton's movie will instantly recognize 1989 as the year that Michael Keaton and Jack Nicholson suited up as Batman and Joker.
In Burton's film, Nicholson's character, Jack Napier, fell into a vat of chemicals -- at Axis Chemicals, in that instance -- that bleached his skin and transformed him into the Joker.
The Joker's origin was first told in 1951, in Detective Comics #168, in which Batman foils the heist of Ace Chemicals by the Red Hood Gang. During a confrontation with the Dark Knight, the gang's leader falls into a vat of chemicals, and emerges with chalk skin, green hair and red lips. Versions of that story were re-told in Batman: The Killing Joke, the 1988 story by Alan Moore and Brian Bolland, and again the following year in Burton's blockbuster Batman.
Airing Thursdays at 8 p.m. ET/PT on Fox, Gotham stars Ben McKenzie as James Gordon, Donal Logue as Harvey Bullock, David Mazouz as Bruce Wayne, Robin Lord Taylor as Penguin, Camren Bicondova as Selina Kyle, Erin Richards as Barbara Kean and Sean Pertwee as Alfred Pennyworth.