A successful FBI profiler, Illeana Scott (Jolie), is summoned to help out Canadian law enforcement in Montreal, to hunt down the serial killer Martin Asher, who assumes the lives and identities of the people he kills as he travels across North America. Illeana has to adjust to working in a strange city with a police team that she does not really fit in with.
The team meets with James Costa (Hawke), an eyewitness who saw Asher kill his last victim. James makes a drawing of Asher and within a couple of days, Asher is found. Illeana discovers Asher's next target is Costa, so protecting him is priority number one. The serial killer dies in a car accident and the case is closed. However, when Mrs. Asher comes to identify the body of her son, the body turns out not to be her son's. Illeana discovers they have been hunting down the wrong guy all that time and they have to come up with a plan to stop this killer once and for all.