The Gravity Thief: Book 3 in the Lucy Nightingale adventures. A child climbs out of Vermeer's Music Lesson to explore the gallery. Two men steal the painting before the boy has a chance to climb back in, leaving him marooned in a strange atmosphere. Curious about why someone wanted this painting and anxious to save the child, Lucy discovers that Vermeer hid five polygons from a drawing by Leonardo da Vinci in the windows of the Music Lesson. Leonardo's shapes were a blueprint for a powerful machine that could be used for good or evil. Lucy and Sam trace the theft to a sick mastermind intent on building a machine that could suck the world into a Black Hole. What begins as a quest to rescue a child becomes a chase to save the world.