In 1999, Bale played serial killer Patrick Bateman in American Psycho, director Mary Harron's adaptation of Bret Easton Ellis' controversial novel. Bale was briefly dropped from the project in favour of Leonardo DiCaprio, but DiCaprio eventually dropped out to star in The Beach, and Bale was cast once again. He researched his character by studying the novel and prepared himself physically for the role by spending months tanning and exercising in order to achieve the "Olympian physique" of the character as described in the original novel. He went so far as to distance himself from the cast and crew to maintain the darker side of Bateman's character. American Psycho premiered at the 2000 Sundance Film Festival to much controversy. Roger Ebert condemned the film at first, calling it pornography and "the most loathed film at Sundance," but gave it a favourable review, writing that Harron had "transformed a novel about bloodlust into a film about men's vanity. " Of Bale's performance, he wrote, "Christian Bale is heroic in the way he allows the character to leap joyfully into despicability; there is no instinct for self-preservation here, and that is one mark of a good actor. "