Twenty-five-year-old Julie Jacobs is heartbroken over the death of her beloved aunt Rose. But the shock goes even deeper when she learns that the woman who has been like a mother to her has left her entire estate to Julie's twin sister. The only thing Julie receives is a key, one carried by her mother on the day she herself died, to a safety-deposit box in Siena, Italy.

In Siena she discovers that her ancestor Giulietta Tolomei met Romeo and their ill-fated love inspired generations of poets and artists. The closer she gets to the treasure they allegedly left behind, the greater the danger surrounding her, superstitions, ancient hostilities, and personal vendettas.