When New York University sophomore Megan Gunther finds personal threats posted to a Web site specializing in campus gossip, she's taken aback by their menacing tone. Someone knows her daily routine down to the minute and is watching her—but thanks to the anonymity provided by the Internet, the police tell her there's nothing they can do. Her friends are sure it's someone's idea of a joke, but when Megan is murdered in a vicious attack, NYPD Detective Ellie Hatcher is convinced that the online threats are more than just empty words.