The film follows the story of Robert Graysmith (Jake Gyllenhaal), a cartoonist who becomes fascinated with the Zodiac Killer case and begins to investigate it. He teams up with Paul Avery (Mark Ruffalo), a journalist, and Dave Toschi (Robert Downey Jr.), a detective who was initially assigned to the case.
The film follows the story of Robert Graysmith (Jake Gyllenhaal), a cartoonist who becomes fascinated with the Zodiac Killer case and begins to investigate it. He teams up with Paul Avery (Mark Ruffalo), a journalist, and Dave Toschi (Robert Downey Jr.), a detective who was initially assigned to the case.