The life of a fictional Irish Catholic priest, Stephen Fermoyle, played by Tom Tryon, from his ordination in 1917 to his appointment as a cardinal on the eve of World War II. Fermoyle goes through one crisis after another, first in his own family and then as he climbs up the ladder of the church hierarchy back in his Boston parish and later in Rome within the Vatican. The film touches on various social issues such as interfaith marriage, sex outside of marriage, abortion, racial bigotry, the rise of fascism, and war.