Batman: The Ultimate Evil is a novel written by Andrew Vachss and published in 1995 by the Warner Aspect imprint of Warner Books. Vachss was an attorney specializing in child abuse cases, as well as a crime novelist best known for his series of books featuring the character Burke, a private investigator who fights against sexual predators. A representative from DC Comics approached Vachss about the possibility of writing a novel featuring Batman. Viewing this as an opportunity to reach a completely different audience, Vachss agreed and wrote a draft. He continued with his themes concerning child sexual abuse and explored the topic of child sex tourism. The publisher required Vachss to follow certain rules, like making a clear distinction between fiction and reality and prohibiting the Batman character from killing, cursing, or having sex.