The only life 12-year-old Emily has ever known is the cold, unloved existence of being an orphan. But everything changes when the Thorntons, a young couple from London, adopt Emily, whisking her away to a new life at their grand estate.
At first, life at Blackthorn Manor is wonderful. But as Emily explores the grounds and rooms, she stumbles upon a mysterious girl named Kat, who appears to be similar in age, and the two become fast friends.
That's when things take a turn for the worse. Kat seems to know a curious amount about the estate, and strange things happen whenever she's around. Like Emily narrowly avoiding getting toppled by a bookcase in the library, or Emily nearly burning her hands when the fireplace erupts in flame. It's almost as if someone, or something, wants her dead.
Emily must find out what happened to the Thorntons and, more importantly, how Kat is connected to these strange goings-on at Blackthorn Manor ― before it's too late!