Uh-oh. Frank isn't doing well at school, and he has just been told off by his head teacher again. He has one last chance to prove himself: all he has to do is follow the rules on his class trip to Chiltern House, complete his worksheet and stay out of trouble. But when a girl steps out of a painting and steals Frank's worksheet, staying out of trouble is easier said than done. Together, they embark on a perilous adventure to discover the girl's lost identity, uniting with new friends along the way who show Frank all is not as it seems in this stately home. How did the owners of Chiltern House come to own its priceless treasures? Can the secrets of the past ever really stay hidden? Will Frank's head teacher stop him and his new friends before they find out the truth? Frank's class trip is more than he bargained for, but it may just hold the greatest lesson he'll ever learn.