Batman
The first Batman story, "The Case of the Chemical Syndicate", was published in "Detective Comics" #27 (May 1939). Finger said, "Batman was originally written in the style of the pulps", and this influence was evident with Batman showing little remorse over killing or maiming criminals. Batman proved a hit character, and he received his own solo title in 1940 while continuing to star in "Detective Comics". By that time, Detective Comics was the top-selling and most influential publisher in the industry; Batman and the company's other major hero, Superman, were the cornerstones of the company's success. The two characters were featured side-by-side as the stars of "World's Finest Comics", which was originally titled "World's Best Comics" when it debuted in fall 1940. Creators including Jerry Robinson and Dick Sprang also worked on the strips during this period.
Batman: The Killing Joke
Batman: The Killing Joke is a 1988 DC Comics one-shot graphic novel featuring the characters Batman and the Joker written by Alan Moore and illustrated by Brian Bolland. "The Killing Joke" provides an origin story for the supervillain the Joker, loosely adapted from the 1951 story arc "The Man Behind the Red Hood!". The Joker's origin is presented via flashback, while simultaneously depicting his attempt to drive Jim Gordon insane and Batman's desperate attempt to stop him.