Sergeant First Class Buck McGriff (Willem Dafoe) and Sergeant First Class Albaby Perkins (Gregory Hines) are two United States Army Criminal Investigation Division (CID) agents on duty in war torn Saigon. When a prostitute is found murdered they discover that the prime suspects are high ranking U.S. Army officers. As they investigate they find that there have been a string of at least six murders in the last year, but the previous inquiry was shut down from higher up the chain of command. Investigations lead them to Colonel Dexter Armstrong (Scott Glenn), but Armstrong rules himself out of inquiries by committing suicide. With the help of a French nun Sister Nicole (Amanda Pays) and their non-commissioned officer in charge, Master Sergeant Dix (Fred Ward), they finally close in on their target. As their investigation leads them closer and closer to the murderer, they find their lives are in danger and they end up nearly being sent home. The movie ends with an unexpected twist when they rule out all their suspects by conducting an interview in a Viet Cong tunnel base, and their NCO is the killer.