At a party celebrating his graduation from engineering school, James W. Bradford confides in Alice Greenway, his father John's secretary, that he received a calling to the ministry years before when he was serving in the military. James then enters the seminary, bitterly disappointing his father, who had planned on having his son join the family's prosperous construction company. After being ordained a minister, James becomes a missionary in New Guinea and cables a marriage proposal to Alice, with whom he has fallen in love. Some years later, after James and Alice have had two children, John receives a cable from Alice informing him that James is gravely ill with jungle fever. Although he has remained bitter over his son's turning to the ministry instead of engineering, John and his wife Dora fly to New Guinea. They arrive in time to see James just before he succumbs to his illness. After James's death, John and Dora bring Alice and their two grandchildren back to the United States. Once home, John reads James's diary and realizes how unselfish his son was. Determined to carry on some of James's work, John takes a leave from his business to travel around the country, speaking to various groups and organizations to encourage donations to foreign missions.