When his companion is killed, challenging Irish investigative Eddie Ryan (Robert Duvall) vows to retaliate the death, whatever the price. As he begins unwinding hints, his actions becomes so horrendous that he's required to kip down his badge, but the experience just pushes him. Ryan ultimately learns that his partner was caught up in a Puerto Rican gun-running scheme masterminded by a crook named Sweet Willie (Henry Darrow), that wants to provoke war of independence.