Costa-Gavras's tense political drama opens in an unspecified South American country (though clearly intended to be Chile) in the throes of a military coup. American activist Charles Horman (John Shea), who has been a thorn in the side of the country's military ever since his arrival, suddenly disappears. In trying to find out what has happened, his wife Beth (Sissy Spacek) is stonewalled, not only by the ruling junta but by the American consulate. His father, staunchly patriotic Ed Horman (Jack Lemmon), joins Beth in her search. Ed and his daughter-in-law have never seen eye to eye politically, and he refuses to entertain the notion that his son's disappearance might be part of a larger conspiracy or cover-up. But as the days grow into weeks, Ed comes to the shattering conclusion that he and his family have been betrayed by the American government, on behalf of the friendly South American dictator who holds his people in a grip of iron. Adapted by Costa-Gavras and Donald E. Stewart from a book by Thomas Hause