When his partner is killed, tough Irish investigative Eddie Ryan (Robert Duvall) pledges to avenge the death, whatever the price. As he starts unwinding ideas, his habits becomes so shocking that he's obliged to turn in his badge, yet the experience only inspires him. Ryan ultimately discovers that his partner was caught up in a Puerto Rican gun-running plan masterminded by a criminal named Sugary food Willie (Henry Darrow), that wants to rouse revolutionary war.