Book excerpt: Although a cease-fire agreement was signed in Panmunjeom on July 27, 1953, fighting between North and South Korea never stopped. The hot war was replaced by a low-intensity war. Terrorism, assassinations, infiltration of spies, and the like replaced tank battles and artillery duels. Until 1993, the United States patrolled its sector of the DMZ (demilitarized zone) in South Korea. In Call Sign: Purple Three, author Mark Heathco, who pulled 385 missions inside the DMZ during his military career, describes the preparation for a dangerous patrol in August 1985. This memoir follows the soldiers as they arrive at Warrior Base, refit for war, and finally execute the patrol itself. With great detail, Call Sign: Purple Three provides keen insight into the Korean DMZ at a time when the world thought all was well in Korea, but in reality chaos was just a hair trigger away. This insiderÕs memoir offers an understanding of what these soldiers did and the sacrifices they made.