Iggy Peck is an architect to his very core. When he isn't making houses out of food, his head is up in the clouds, dreaming of brilliant new designs. So, when Ada Twist’s Aunt Bernice inherits an old, sprawling mansion from an ice-cream mogul, Iggy is completely blown away! The house is packed with countless rooms from all his favorite architectural periods. But something is not quite right in the grand old house. Everyone in town claims the mansion is haunted, and strange things keep happening. Even worse, a collection of priceless antiques—which Aunt Bernice desperately needs to pay for the house's upkeep—has mysteriously gone missing. If they cannot find the missing treasures soon, Aunt Bernice might lose the house forever! It will take all of Iggy’s incredible knowledge of architecture, plus the help of his best friends Rosie Revere, Ada Twist, and Sofia Valdez, to crack the case. Jump into this exciting chapter book adventure and use your own problem-solving skills to help the Questioneers find the treasure!