Lost

Emma Duval has a sister, a sister who's been kept secret. She was taken the day she was born by a man who wears a mask. Emma was only 1 and remembers nothing and Emma's mother never thought she'd see her youngest daughter again so she never told Emma about her.

15 years later a killer is back, and Genevieve is so close to her family, but if she tries to leave where she's being kept her mother and sister will die.

She's stuck and scared. So she writes a letter and doesn't expect a reply....but gets one...