Since its first premiere in 1971, a classic Republic of Vietnam (1954-1975) war romance feature based on a fiction novel by military writer, Van-Quang. The film was lost for more than 4 decades when the communist forces took Saigon, Republic of Vietnam's capital, on April 30th, 1975. Digitized and restored from surviving 35mm prints archived by Japan film studio Imagica Lab; now transferred to UCLA Film and TV Archive. This film provides an almost unknown perspective on the Vietnam War, the Republic of Vietnam, and the RVN Army. The stage is the Republic of Vietnam, and the scenes portray a time during the Vietnam War as experienced by the Southern Vietnamese people, themselves. Phi, a soldier, longing to take Lien off to their private, imaginary space (the Purple Horizon), understands what his duty and commitment as a soldier is. Lien is a singer whose style is reminiscent of the "Torch" singers of the early 1930s. She desperately longs to escape the world with Phi to their purple.

The Joint Chiefs of Staff want to send some ARVNSF troops to North's Điện Biên Phủ for the Dien Bien Phu Operation. But all have been caught or killed by Chinese spies as Kiều Loan, except Major Ngọc Minh.

TV series based on Hồ Biểu Chánh novel of the same title.