Deloris Van Cartier is again asked to don the nun's habit to help a run-down Catholic school, presided over by Mother Superior. And if trying to reach out to a class full of uninterested students wasn't bad enough, the sisters discover that the school is due to be closed by the unscrupulous chief of a local authority.
A Reno singer witnesses a mob murder and the cops stash her in a nunnery to protect her from the mob's hitmen. The mother superior does not trust her, and takes steps to limit her influence on the other nuns. Eventually the singer rescues the failing choir and begins helping with community projects, which gets her an interview on TV—and identification by the mob.
When an in-flight collision incapacitates the pilots of an airplane bound for Los Angeles, stewardess Nancy Pryor is forced to take over the controls. From the ground, her boyfriend Alan Murdock, a retired test pilot, tries to talk her through piloting and landing the 747 aircraft. Worse yet, the anxious passengers — among which are a noisy nun and a cranky man — are aggravating the already tense atmosphere.
Belgian nun Sister Ann is sent to another order where she's at first committed to helping troubled souls, like Nichole and little Dominic. When Father Clementi hears Sister Ann's uplifting singing style, he takes her to a talent contest. Sister Ann is signed to a record deal and everyone is listening to her lighthearted songs. She is unprepared for her newfound fame (like appearing on The Ed Sullivan Show) and unwanted side effects, including a wrongful attraction to an old friend.
1962. A crystalline voice becomes a planetary tube. A Belgian nun jostles Elvis and the Beatles on the world charts. Her name: Sister Smile. A popstar with the trajectory of a comet who understands her success no more than the double meaning of her words… The harder the fall will be. Even God does not protect sharks' appetites or pretenses of success! Who killed the little voice of God? Here is the tragic story of an innocent voice, of an extraordinary fate, almost of a curse ...
Celestin is the singing teacher in a monastery and Denis is one of her students. They both dream about the life outside. (It's a Swedish version of the famous vaudeville-opérette "Mam'zelle Nitouche").