Based on a true story, a young American soldier fighting in the Vietnam War meets a beautiful Vietnamese woman on his base. Their relationship develops into a full romance leading to an engagement, but the turmoil of the times and their parental opposition leads to heavy resistance. Fellow soldiers and officers attempt to talk him out of the marriage, but the two are determined to marry, despite the ongoing war.

Destiny has its hand against it, as the US Army sends the soldier home to finish his service stateside, leaving his Vietnamese fiancee in-country with his promise to her, "I'll come back for you." When he settles into his new assignment in the United States, his letters to her go unanswered. As months go by, he is concerned for her safety in the war and launches an on-base search for her as he contacts embassies, consulates, and a US senator, as well as a chaplain still in Vietnam.

When this search through established channels fails to locate her, she is considered officially missing somewhere in Vietnam. Remembering his promise, he begins preparation to return to Vietnam and find her to deliver on his promise to marry her. His search takes him as far south as the Mekong Delta, as far west as the Cambodian border, before crossing enemy lines in the Central Highlands, where he finally finds her.

His only problem now is, he has to fight to get her back. She has been promised to another man in an arranged marriage. Worse than this, he has discovered her father as part of the Viet Cong. His resistance to let her go leads to a confrontation between himself and the enemy.