Francis Coppola struggled in regard to how to end Apocalypse Now.  Earlier in the movie's production, Coppola had some of the local Ifugao people brought onto the movie set to play the role of Vietnamese and Cambodian montagnard tribesmen.  It was Coppola's wife who, upon witnessing the sacrificial slaughter of a Carabao (water buffalo) by the Ifugao, finally found a resolution to her husband's dilemma.  Purportedly not initially interested, Francis Coppola, at the behest of his wife, went to witness one of the sacrificial rituals performed by the Ifugao, and finally found a way to end his movie.