¡Se armó el belén!.

An old priest, who has old ideas, is intended to exercise the apostolate in a neighborhood in the suburbs of Madrid. There the revolutionary climate and anti-religious character of the congregation thwarts all his attempts to attract them. The Archbishop admonishes him and asks to renew his methods, using the example of a young priest of a modern parish. The old priest tries to apply in his environment what he has seen in the parish model, setting off a chain of events.