Four extraordinary children must avenge their friend's death, try to save their home, and unravel the secrets of their past before their past unravels them. Pippa, Sam, Thomas, and Max are happy to be out of harm's way now that the notorious villain Nicholas Rattigan is halfway across the country in Chicago. But unfortunately their home, Dumfreys's Dime Museum of Freaks, Oddities, and Wonders, is in danger of closing its doors forever. But their troubles only get worse. The four friends are shocked when their beloved friend, famous sculptor Siegfried Eckleberger, is murdered. As they investigate, they find clues that his death may be tied to the murder of a rich and powerful New York heiress, as well as to their own pasts.