Zodiac is a crime thriller helmed by David Fincher that explores the hunt for a serial killer who terrorized the San Francisco Bay Area during the late 1960s and early 1970s. The film, based on Robert Graysmith's nonfiction books, follows investigators and journalists as they pursue a killer known only by the cryptic messages and ciphers he sends to newspapers. The ensemble cast includes Jake Gyllenhaal as cartoonist-turned-investigator Graysmith, Mark Ruffalo as Inspector Dave Toschi, and Robert Downey Jr. as crime reporter Paul Avery.