On a winter night in Boston, a man falls to his death in front of a train. The sole witness, a shaken young woman, explains to the police how the man shoved her aside as he made his way to the tracks. But when her blog turns up on the dead man's computer, the cops begin to look for other connections between them. This dark and intricate tale of obsession and deception is told in the form of a blog written by an elusive narrator known only by her online...