Rachel is a rambunctious teenager from a fundamentalist Mormon family in Utah. On Rachel's 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, Rachel turns up pregnant and claims to have had an immaculate conception from listening to the music. Rachel's parents arrange a marriage for Rachel, but Rachel runs away to the closest city, Las Vegas, to search for the man who sings on the cassette tape, thinking he has something to do with her mysterious pregnancy...