The rock group, Sonny and the Sundowners, is appearing at Carlos' casino. Sonny is an old friend and musical partner of Sister Bertrille's when she was plain old Elsie Ethrington, and she goes to see him. He is thrilled to see her but surprised at her choice of career. When in the natural course of conversation she tells him that the convent is short of money, he suggests to her that she write a song for the group, whose last record sold more than a million copies. He will even give her an advance. Sister Bertrille is excited, and in discussion with the other sisters, they decide not to tell the Reverend Mother of the arrangement, because rock music is in her mind unbecoming and she will probably not approve of the convent making money through such. So the sisters all take on Sister Bertrille's chores while her main task is to compose. After some struggle, she comes up with a simple, pretty, acoustic song. Although the song's not quite in the tone of the Sundowners' music, Sonny likes it, but tells her he needs to tweak it to fit the Sundowners' groove. The song is to be debuted at the concert at the casino to which the sisters are invited. The day of reckoning comes for telling the Reverend Mother; but it's too late as she already knows. She approves of the arrangement and is only disappointed that they felt the need to keep this from her. She even wants to attend the concert with the other sisters. Sister Bertrille's song is the first one sung at the concert. Or is it really Sister Bertrille's song. Sonny has turned it into a psychedelic head-trip rock song. The Reverend Mother is not amused. Sister Bertrille is also not amused, but is more disappointed. She feels she can't accept the advance for the song since what Sonny and the Sundowners performed was not her song. It isn't until Sister Bertrille performs the song the way that she wrote it that the Reverend Mother understands. So does Manny Julian, Sonny's manager, who still wants to use the song and pay the sister for it. Instead of for Sonny and the Sundowners, Manny will give the song to his one other client: The Salt Lake City Boys Choir.
—Huggo