Thousands of fanboys and fangirls awaiting their Citizen Kane stormed the San Diego Convention Center on July 25 to see advance footage of WATCHMEN, directed by Zack Snyder (300) and due in theaters next March. Based on Alan Moore's graphic novel--which TIME's critics named one of the 100 best novels since the magazine's founding in 1923--the film is set in an alternate 1980s world where Richard Nixon is still President, cold war tensions run high and superheroes are being murdered. Snyder's teaser showed arresting visuals of the giant blue Dr. Manhattan (Billy Crudup) atomizing some Viet Cong, fellow crusaders Nite Owl II (Patrick Wilson) and Silk Spectre II (Malin Akerman) kissing in front of a mushroom cloud and the coarse Comedian (Jeffrey Dean Morgan) plunging to his death from a window, with a blood-spattered smiley face--the book's trademark--tumbling after him. With its dense story line, Watchmen asks a lot of its audience, and Snyder is wrestling with a three-hour cut of the film. But Comic-Con's diehards rise to a challenge. They happily viewed the footage twice.