When twelve-year-old Dana Shannon starts to strip away wallpaper in her family's old house, she's unprepared for the surprise that awaits her: a hidden room containing a human skeleton! How did such a thing get there? And why was the tiny room sealed up? With the help of a diary found in the room, Dana learns her house was once a station on the Underground Railroad. The young woman whose remains Dana discovered was Lizbet Charles, a conductor and former slave. As the scene shifts between Dana's world and 1856, the story of the families that lived in the house unfolds. But as pieces of the puzzle begin to fall into place, one haunting question remains: Why did Lizbet Charles die?