WARNING: This article contains spoilers for the latest episode of Gotham, "One Bad Day."
Television's Batman origin story, Gotham, is giving fans its very own spin on the mythology of the comic books. More often than not, it's taking extensive liberties in delivering origin stories for characters like Penguin, Solomon Grundy and Azrael. However, sometimes, the series will dive into the source material to give us more comic book-accurate story beats. It's that healthy blend that has helped make Gotham what it is today, and why most of its fans have come to accept it as an Elseworlds-type of story that tells its own tale.
One story that is nowhere to be found in the source material is the veritable spider-web of an origin story that the series is weaving for the Joker. On Gotham, the character was splint in two, first in the form of Jerome Valeska and now, his twin brother Jeremiah. However, behind these two lies the idea of the Joker as it always was in the comics. And, to help hammer away that idea like never before, the series' latest episode partially adapted the quintessential Joker graphic novel, Batman: The Killing Joke.
In "One Bad Day," Gotham presented its own take on some of the classic story beats of The Killing Joke. The 1988 comic, which was written by Alan Moore and illustrated by Brian Bolland and John Higgins, was seminal in its approach to the Joker. It explored the character at his most sadistic, which culminated in the crippling of Barbara Gordon (a scene that Gotham brutally paid homage to), all while giving us an origin story to help explain why Joker was the way he was. But more than that, it examined the fine line between Batman and Joker. It showed us how alike the two actually were, if they weren't so fundamentally different. To this day, The Killing Joke is still presented as one of the most important works in the DC Comics library, and with very good reason.
Because of its acclaim and importance in the pantheon of Batman's comic book history, it should be no surprise that Gotham decided to use it in its ongoing Joker saga. However, instead of doing a full-blown adaption, the series smartly decided to mold the idea to the story they were already telling. Since the series had already established the idea that Bruce and Jeremiah had developed a friendship, the groundwork was already laid for an exploration of what separates the two, and what divides friend from hero. The maniacal genius Jeremiah, in his own warped views, sees Bruce as his best friend. And what he wants for his best friend is to be mad, just like him.