The Girl from Perfume River

It began when a newspaper editor assigned an investigative piece to an Asian-American reporter and became, with the discovery of her aunt's carefully typed memoir, a journey back in time to the final days of French colonial rule in Indochina where a young Vietnamese woman must choose between love and duty. When a priceless artifact is stolen from a Saigon museum, she searches for the valuable item without help from the police.
Threatened by a crime organization, she and an American correspondent (who have fallen in love) flee Saigon, pursued by hired killers.