An out-of-work TV reporter/cameraman, Dylan Haggerty, stumbles upon the story of the century when his mysterious old ex-Marine neighbor, Walter Ohlinger, tells him on camera that he was the second gunman on the legendary "grassy knoll" in Dallas who actually killed John F. Kennedy. Walter, who is deteriorating from cancer, asserts that Lee Harvey Oswald was set up as a patsy, while he carried out the mission. This leads Dylan into a race to prove the 'second gunman' claim, which could finally close the books on one of the most researched conspiracy theories of all time. The search sends them from Dallas to Washington, D.C.