A careful, methodical young data analyst for a California insurance company, John Walker knows when people will marry, at what age they will most likely have children, and when they will die. All signs point to a long successful career---until Max Stillman, a gruff security consultant, appears without warning at the office. It seems a colleague with whom Walker once had an affair has disappeared after paying a very large death benefit to an impostor. Stillman wants to find and convict her; Walker is convinced the woman is innocent. Now Walker teams up with Stillman on an urgent north-by-northeast race---relentlessly leading to a pay-off that just might shock the life out of him.