Vietnam, 1963. A female Viet Cong assassin is trawling the boulevards of Saigon, catching US Army officers off-guard with a single pistol shot, then riding off on the back of a scooter. Although the US military is not officially in combat, sixteen thousand American servicemen are stationed in Vietnam `advising` the military and government. Among them are Ellsworth Miser and Clovis Robeson, two army investigators who have been tasked with tracking down the daring killer.