In Philadelphia, psychologist Dr. Liz Manners hosts a relationship advice segment on WLOR Talk Radio. During one episode, she advises a caller named Sara Jane to escape her violent and controlling husband, Kyle Lundstrom. Following her advice, Sara attempts to flee but is tragically struck by a car and killed while being pursued by Kyle. Enraged, the deranged Kyle vows to ruin Dr. Manners’ life. Disguising himself as an investor named James, he infiltrates her life by befriending her husband, Rob, and begins to sabotage their marriage.