The Gathering (movie, 2001)

Cassie Grant (Christina Ricci) is a young girl from the United States who is wandering through England on foot. On her way to Ashby Wake Cassie is hit by a car. The driver of the car, Mrs Marion Kirkman (Kerry Fox), immediately calls an ambulance. During an examination at the local hospital the doctor comes to the conclusion that Cassie only has some scratches and not even a concussion, but Cassie has lost her memory due to the accident. She only knows her name and mother country, but she does not know which town she comes from, who her family is and why she is in England.