Felice Cristy is not a nun, but she's posing as one at a desert convent to protect a controversial sister threatened by extremists. Felice is a private investigator in Palm Springs, California, who encounters a man hiding his own identity as an FBI agent for the same purpose. Together, as they reluctantly fall in love, they survive days in the Sonoran Desert and attacks by two sets of opponents as they struggle together to keep Sister Mary Grace safe.