Based on the celebrated graphic novel by Alan Moore and Dave Gibbons, the exciting and dark "Watchmen" takes place in Tulsa, Okla., 34 years after the original story. After a white supremacist attack on the local police department, which leaves only two surviving cops on the beat, laws are passed that allow the cops to hide their identities behind masks. One of these cops, Angela Abar, adopts the identity of Sister Night and fights racists while dealing with the decades-long legacy of the vigilantes.