The Woman Who Believed (1922)

John Grimm, a recent engineering graduate, is offered a position to complete an irrigation barrage in the jungles of Africa. He is encouraged to accept the assignment by his secretary, Mary Westlake, his childhood sweetheart. Mary is deeply in love with John but keeps her feelings secret because he has affirmed that he will never marry. Once in Africa, John finds that the irrigation project has been beset with problems, many because of the incompetence of the former supervisor, Dugan. Bitter and jealous of John, Dugan hires Dick Morton to sabotage the project. To stop Morton, Mary, who suspects him of undermining John, goes to his tent. As she attempts to convince Morton to switch his loyalties to John, John enters the tent and realizes that he is in love with Mary. After a series of misadventures caused by Arab attacks, lions and the dynamite explosion of a bridge, John is able to complete the irrigation project. John and Mary then return home to begin their life together.