Young and vibrant New Orleans criminal psychologist Kit Franklyn has just been assigned her most challenging case yet—a collection of victims with similarities that include driving old cars, humming nursery rhymes, committing murder, and then killing themselves! Welcoming the help of her jovial boss, chief medical examiner Andy Broussard, the two set out to solve the case, thinking only along strictly scientific lines. Not once do they consider the involvement of Black Magic, a New Orleans cultural staple, until an ancient Cajun sorcerer's curse surfaces with an ominous warning: "Beware the songs you loved in youth."