Final Curtain ─ Saigon

In July 1974, Air Force Lieutenant Colonel Terry Lawson accepts an assignment in Thailand to fill a career development objective and recover from five grueling years of developing sophisticated computer systems for the Air Force. He also wishes to get over a failed marriage and renew his love affair with the C-130, the aircraft he flew in combat in Vietnam. But most importantly, he wants to relax, enjoy himself, and become immersed in the Thai culture.
Lawson is well along in satisfying these objectives when he is asked to fly to Saigon to assist the United States Embassy's Defense Attache Office in fixing problems with their intelligence systems. In a matter of days, he finds himself drawn into the dark world of CIA operations by a cultured and attractive French-speaking Vietnamese woman, Lan Le Ninh. Finding both her and the nature of the work compelling, Lawson voluntarily abandons his life of leisure in Thailand.
From this point on, it's a race to correct the aberrant systems before the North Vietnamese communists launch their long-feared final offensive. In the process, Lawson learns a great deal about America's long-running secret war in Southeast Asia-and how many Americans died anonymously in carrying it out.