Secret of Epping forest

It's early summer as young Rose Fair travels to England from California with her parents. The house where she is staying has many secrets, and so does the forest behind it. Unfamiliar with rural life, Rose quickly becomes enchanted-and most of all curious-as she stumbles upon a secluded mansion. The residents, Edmond and Thackeray, don't seem to be from the area. They don't even seem to be from this era! Rose unravels their secret but then must choose whether she will stay or go. And she has just until summer's end to decide.