Rachel is a rambunctious teenager from a fundamentalist Mormon family in Utah. On her 15th birthday, she discovers a forbidden cassette tape with rock music on it. Having never heard anything like it, Rachel has a miraculous experience. Three months later, she turns up pregnant and claims to have had an immaculate conception from listening to the music. Rachel's parents arrange a marriage for her, but she runs off with her brother, "Mr. Will," to Las Vegas to search for the man who sings on the tape, thinking he has something to do with her mysterious pregnancy. There they meet Clyde, a young rocker who challenges everything they've been taught and changes the way they see the world.