Her is a well written book told in alternating chapters / voices. The story of two "friends", Nina and Emma. Nina recognizes Emma but Emma is unaware of who Nina is Nina pretends to be friendly and caring, weaving her way back into Emma's life in some very unusually cruel ways. The past of these two is never disclosed. The book ended rather vaguely, leaving me to wonder if I had missed something. A few more details of this "friendship" would have tied up the loose ends,