Stephen can't remember his mother, and no one will talk to him about her. He knows she left when he was four years old, but he's not sure why - she could be dead for all he knows. Things take a strange turn when Stephen starts finding keys which open mysterious doors - doors which lead into a strange world where everyone knows Stephen, and calls him by name, but he doesn't recognize anyone. Eventually Stephen works out the secret behind the doors - and also finds out the very surprising truth about his mother.