Father Francis Chisholm (Gregory Peck) is visited in his old age by Monsignor Sleeth (Sir Cedric Hardwicke) at his fictional Scottish parish of Tynecastle in Tweedside. The Monsignor informs Francis that the Bishop thinks it would be better if he retires. Father Francis' journal recounts his story from 1878 in flashback.
Francis' father, Alec Chisholm (Dennis Hoey), was beaten by an anti-Catholic mob. After, he and Francis' mother (Ruth Nelson) both die in a bridge collapse. Young Francis (Roddy McDowall) is raised by his Aunt Polly (Edith Barrett) until he leaves for the seminary with Anselm "Angus" Mealey (Vincent Price). Francis, still in love with Nora (Peggy Ann Garner), a girl from his home town, learns the had a child out of wedlock with another man. She dies, giving birth to a daughter, Judy.
Bishop Hamish McNabb (Edmund Gwenn) suggests that Francis volunteer for the missions in China. Francis accepts, and arrives in Pai-tan, China to find that the mission has been destroyed by floods.
A young Christian Chinese, Joseph (Benson Fong), offers to help rebuild the church, and Francis is humbled by the man's Christian spirit. They create the St Andrews Christian Mission.
Francis receives a shipment of medical supplies from his childhood friend, Dr. William (Willie) Tulloch (Thomas Mitchell). An old woman comes with her granddaughter and asks that Francis care for the child when she, the old woman, dies.
Francis is summoned by Mr. Pao (Philip Ahn), Envoy for local official Mr. Chia (Leonard Strong), to cure Chia's only son of an infection. Francis saves the boy. Chia donates land and laborers to rebuild the mission. Three nuns arrive and set up further Christian provisions. The Reverend Mother Maria-Veronica (Rose Stradner, as Rosa Stradner), a cold woman born into nobility, causes friction with Francis.
Two years later, Willie visits from Scotland and is able to create a makeshift hospital. The mission is destroyed along with much of the town in a series of fires caused by imperial troops battling republican forces. Willie is fatally shot and dies in Francis' care.
Later, Angus arrives as part of a review of missionary sites. He tells Francis that Bishop McNabb is dead.
Ten years pass. Francis goes to Pai-tan to visit a new Protestant mission Methodist Church, run by rival American Rev. Dr. Wilbur Fiske (James Gleason) and his wife, Agnes Fiske (Agnes Fiske).
Years pass. Francis reaches retirement age and two young priests come to replace him. Francis plans to look after Judy's son, Andrew (Georgie Nokes), when he goes back to Scotland. On his final day the townspeople line the street as Francis drives through in an open top car. Francis blesses the crowd.
The flashback ends, and Monsignor Sleeth admits that he won't be telling the Bishop anything is amiss at Francis' parish, leaving him free to continue serving his parish, and raising Judy's orphaned son, Andrew. They get their fishing rods and head off.
A 1944 American missionary war drama film directed by John M. Stahl, produced by Joseph L. Mankiewicz, screenplay by Mankiewicz and Nunnally Johnson, based on A. J. Cronin's novel "The Keys of the Kingdom" (1941), cinematography by Arthur C. Miller, starring Gregory Peck, Thomas Mitchell, Vincent Price, Rose Stradner, Edmund Gwenn, Benson Fong, Roddy McDowall, Sir Cedric Hardwicke, Dennis Hoey, Ruth Nelson, Edith Barrett, Peggy Ann Garner, Jane Ball, James Gleason, Anne Revere, Benson Fong, and Si-Lan Chen.
Rose Stradner was the wife of Joseph L. Mankiewicz.
Alfred Hitchcock liked the novel and hoped to direct it, but opted to direct "Lifeboat" (1944).
Variety called this a "cavalcade of a priest's life, played excellently by Gregory Peck."
The film was nominated for Academy Awards in the following categories:
Best Actor in a Leading Role (Gregory Peck)
Best Art Direction-Interior Decoration, Black-and-White (James Basevi, William S. Darling, Thomas Little, and Frank E. Hughes)
Best Cinematography, Black-and-White (Arthur C. Miller)
Best Music, Scoring of a Dramatic or Comedy Picture (Alfred Newman)
Alfred Newman incorporated Irish and Chinese elements into the score.
In a 2010 review, film critic Jay Carr wrote: "Again and again, one is impressed by the depth of talent on studio rosters of the time, in this case 20th Century-Fox. Not just Gwenn, Mitchell, Hardwicke, and Price, but James Gleason, Roddy McDowall (Chisholm as a boy), Peggy Ann Garner, Anne Revere and Benson Fong dot the cast list in this solidly crafted film - measured, stately, patient, never loud or pounding (except when the mission is caught in a war between imperial and nascent republican troops, and Father Chisholm briefly takes up arms!). It would have to be because it's essentially a film about interiority translated into service, a film of cumulative increments...The bottom line is that The Keys of the Kingdom and Peck convince us they're about a man in a cassock spending his life trying to do the right thing."