While enjoying a fabulous party hosted by wealthy Joanna Tate, Nancy finds herself investigating a major jewel theft. Joanna's newest prize -- a diamond and ruby necklace -- is missing. And since Joanna hasn't kept the necklace a secret, Nancy has plenty of suspects. Her chief problem is rookie police detective John Ryan, who wants to nab the thief himself. But a rash of copycat robberies -- and some devishly original murder attempts -- convince Nancy to collar the country club burglar right away... or pay dearly later.