Young Iggy Peck is an architect at his very core: when he’s not making houses out of food, he's dreaming of design. So he’s totally blown away when Ada Twist’s Aunt Bernice inherits an old house from ice-cream mogul Herbert Sherbert, filled with countless rooms from all his favourite architectural periods. But something’s not quite right… Everyone says the house is haunted and some priceless antiques have gone missing. If they can’t find those antiques, Aunt Bernice might lose the house forever. It will take all of Iggy’s knowledge of architecture and the help of the other Questioneers – Rosie Revere, Ada Twist and Sofia Valdez – to solve the mystery and find the treasure!