After solving her first mystery, sixteen-year-old Jessica Prince?the niece of billionaire Henry Prince?thinks her sleuthing days are over. But during a charity auction at an art gallery in her hometown, the lights go out and an expensive painting is stolen before the thief leaves a white lily behind and escapes.

Jessica doesn't know why her hometown is so spooked until Mayor Forrester explains the unsolved case of a group of thieves called the White Lily Society. They left white lilies in place of whatever they stole and vanished years ago, never to be seen or heard from again. It isn't until Prince Manor is broken into and a white lily is switched for her grandfather's bust that she realizes the thieves have returned?with a target on Jessica's back.

As the thefts worsen and Jessica's friends become the thief's focus, she must once again rely on her love of mystery novels and observational skills to stop them before they hurt someone. But Jessica isn't prepared for what she discovers?that the Prince family might know more about the White Lily Society than her Uncle Henry wants to admit.