Olivia and Dan Felbeck are blissfully happy when their longed-for twins arrive after years of IVF. At the same time, they make the move to Renniston Hall, a huge, Elizabethan house that belongs to absent friends. Living rent-free in a small part of the unmodernised house, once a boarding school, they can begin to enjoy the family life they've always wanted. But there is a secret at the heart of their family, one that Olivia does not yet know. And the house, too, holds its darkness deep within it.