Nancy Bond introduces the two families of the Ibbetsons and the Prines who are forced together when the divorced Prine mother Valerie maries the widowed Ibbetson father Edward. Valerie is an archaeologist who is excavating the ruins of a Roman fort on Hadrian's Wall in the Northumbria region of England, and that is why the family must move to Wintergap, a gloomy house built in the harsh climate of northern Britain. 

Penelope, the only Ibbetson daughter, is the first to sense the dark history of the house. Penelope must learn how to bring back together the divided land, and somehow make amends. The story is thought provoking, suspenseful, and filled with historical accuracy and astonishing details.