(5/22/2014)
This is a really great, creepy thriller. Nina recognizes Emma on the street from when they were teenagers more than 20 years before, but Emma has no idea who Nina is. Nina then insinuates herself into Emma's life, by pretending to be friendly and kind, but with underhand, sinister motives. It's cleverly written in alternate chapters by Nina and Emma, and the tension builds slowly and effectively towards the end. The ending is a cliffhanger, which leaves you wondering what exactly happened.