This is San Juan, Puerto Rico. And this is the Convent San Tanco.
Sister Jacqueline and Sister Sixto have to walk when the car does not start. Sister Bertrille comes off the boat in high wind. Weighing only ninety pounds, she falls into the water and swims to a boat where Carlos is engaging in passionate discussion with a lady, who sees the wet nun behind him. Sister Bertrille plays gin with bikini-clad women and gets them to agree to attend Mass since they lost. She meets Sister Jacqueline and Sister Sixto and casually mentions she was in jail for attending a free speech rally.
They arrive at the Convento San Tanco which has problems. Sister Bertrille says she feels like she's home.
Sister Bertrille says she used to wish she could be a bird. Sister Jacqueline says people say the cornet they wear looks like like a bird. A gust of wind sweeps by and causes Sister Bertrille to hover.
At dinner, Sister Jacqueline informs Sister Bertrille that the Reverend Mother is old-fashioned. She has Sister Ana take her to the kindergarten where she is introduced to the orphans.
She sings with them. "We've got a lot of things to do." They join in. "Felicidad is the happiest word, happiest word that you have ever heard." She takes the children all over and spreads enthusiasm throughout the convent. The children paint the station wagon a lavender color while Sister Bertrille fixes it.
Reverend Mother Placido arrives and reprimands her irreverence and making crazy clothes for the children. Sister Bertrille says she wants to attract attention so people will know the plight of the convent. Reverend Mother says she has young ideas. Even if they had money, they would not have land. Sister Bertrille says she saw some good land. Reverend Mother says Carlos Ramirez, the owner, would not sell it, but Sister Bertrille goes to meet him anyway.
Sister Bertrille arrives at a club where everyone is dancing. The people stop dancing when they see a nun in there. She sneaks up behind Carlos who is dancing with a lady. Carlos takes her to his office. She asks him about the vacant lot, but he says he is building a house and will not sell. He declines to donate the land. "Sister Bertrille, do me a favor, and don't come to my discotheque again."
Later, she goes to a pool where Carlos is talking to a woman. The woman asks if nuns swim. Sister Bertrille reels them in to the side of the pool. She informs him she found another piece of land, but he still refuses.
"Señor Ramirez absolutely refuses. He's a very stubborn man," she tells Sister Jacqueline. The wind lets her hover again, and while Sister Jacqueline tells her about Carlos, she flies away. The Reverend Mother comes and Sister Jacqueline shows her Sister Bertrille flying away.
Sister Bertrille flies around and approaches the ocean. She descends and walks on water. A submarine comes out of the water and she lands on it. A sailor sees her and approaches the captain. She flies away before the captain comes up to see her. The sailor says he's Jewish so he could not have had a vision because he would have seen a rabbi.
Carlos takes a woman to an airport anxious to get away from Sister Bertrille. He is delighted when the person behind him is only the pilot.
Sister Bertrille flies over an island where a man is hunting ducks. He points his gun up. "Hey! Cut that out!" she yells. He runs away in terror. She sees Carlos's plane.
Carlos is being romantic to the woman and sees Sister Bertrille out the window. Carlos says they must go back to San Juan to donate his land. "I just had a religious experience."
Sister Jacqueline and the Reverend Mother worry about Sister Bertrille.
Sister Bertrille flies over a restricted area. The nightguards find her in the garbage where she falls.
The major thinks she could be a foreign spy and questions her. She tells the army men she flew in and hit a down draft. She says her flight is like the pelicans. "Tell me. Does lift plus thrust mean anything to you?" she asks, and tries to explain how she flies.
Sister Jacqueline and Reverend Mother arrive by helicopter along with Captain Dominic Lopez of the police. Needing a witness, Sister Bertrille says Señor Ramirez saw her. Reverend Mother says he's at the convent.
They go to the convent where Carlos reveals he intended to donate his land since he saw Sister Bertrille flying. Reverend Mother thinks he will redraw his offer since it was not really a religious experience, but he still offers it. Before leaving, the army major tells Sister Bertrille she should take a navigation course.
"Sister Bertrille! Why are you looking so down in the teeth?" Sister Sixto calls the next day. Sister Bertrille says the Reverend Mother has not made a decision yet. The children come up and sing to her. "You've got a lot of things to do...Felicidad is easy to feel..." They cheer her up. Sister Ana informs her the Reverend Mother wants to see her.
The Reverend Mother tells her, "I leave the problem of flying up to your conscience." As she is about to leave, a Mr. Sullivan calls long-distance from New York. "Ed Sullivan!? No, Mr. Sullivan, I couldn't possibly appear," she says over the phone.