 Dr. Jennifer Ethrington, Sister Bertrille aka Elsie Ethrington s older sister, is coming by San Juan en route to Brazil where she is to work in the small remote villages. Sister Bertrille is worried that her sister may be bored by the rather sedate lifestyle of the convent during her stay. But her stay will be anything but sedate as she meets Carlos Ramirez on the flight into San Juan, Carlos who has become smitten with her. Although Jennifer mentions that she has a sister at the convent, Carlos doesn t know it s Sister Bertrille. And although Jennifer mentions to her sister that she has a date with a local, Sister Bertrille doesn t know it s Carlos until he comes by the convent to pick Jennifer up. Despite Carlos being her friend, Sister Bertrille is worried about Jennifer going out with Carlos. The truth for everyone comes out when Sister Bertrille barges in on Jennifer and Carlos  date. Jennifer implies to her sister that she s a big girl who can take care of herself. But Sister Bertrille s prayers are answered when the Reverend Mother asks Sister Bertrille to ask Jennifer to go out to a remote village to take care of a rabid dog bitten patient. For Sister Bertrille, it s just in time as Carlos has just asked Jennifer to marry him. As Jennifer thinks about the proposal, Carlos, Jennifer and Sister Bertrille fly off in Carlos  plane to the village. The trip is a disaster for Carlos in his perception of how Jennifer sees him as a potential mate living in the outback of Brazil - he falls in a swamp, faints when helping Jennifer with the patient, and in an accident falls on some broken glass which requires some stitches in his derrière. Carlos is mad about the situation and mad at Sister Bertrille, who he thinks has purposely sabotaged his relationship with Jennifer who has declined his proposal. Sister Bertrille is upset that the damage to their friendship may be irreparable. But Jennifer clears the air with Carlos, this act repairing his friendship with Sister Bertrille. Jennifer tells him that her sister had nothing to do with her declining his marriage proposal. To make Carlos even happier, Jennifer reminds him that if they did get married, Sister Bertrille would become his sister-in-law, which he s not quite ready for.