In the 1960s and '70s, a cryptic killer clad in an executioner's hood stalked the streets of San Francisco and left clues about his crimes in the newspaper. In director David Fincher's chilling recount of the murders, Oscar nominee Jake Gyllenhaal -- flanked by an impressive ensemble cast that includes Robert Downey Jr. and Chloe Sevigny -- stars as reporter Robert Graysmith, the man who went on to write the best-selling true crime book Zodiac.