Incident in Saigon.

In transit to Saigon, Jean Dartigues wants to see Nicole, whom he once knew and secretly loved. The young woman, now a widow, is a high school teacher. However, the police have just uncovered a story of arms and drug trafficking and are forbidding passengers to leave the airport. With the help of a bartender, Jean manages to get into town. At school, no Nicole, but he meets a young Vietnamese girl who offers to help him with his research. One thing leading to another, one adventure leading to another, Jean finds himself involved in the trafficking operation, first unwittingly, then of his own free will, when he realizes that Van, the young Vietnamese woman involved, is risking her own life. With the help of the girl's family and a sympathetic policeman, Jean manages to have the gang arrested, and, taking the plane back to France - very temporarily - he entrusts Van, who has become his most precious possession, to Nicole, who has finally been found and is somewhat melancholy.