Based on a true story, Chattahoochee depicts the life of Emmett Foley (Gary Oldman), a Korean War hero who becomes an unlikely crusader on behalf of mental health patients. Unable to adjust to life after the war, Emmett quickly falls apart; after a showdown in which he taunts the cops, he's thrown into the Chattahoochee State Mental Hospital. His hard-luck story turns into a bigger nightmare when he discovers just how inhumane the institution is.