Katie, a mysterious 27-year-old woman, moves to Southport, North Carolina. She maintains privacy at an extreme level, starts working at a restaurant named Ivan's, and lives an isolated life without involving herself in anything social. It is apparent that she is hiding a secret. She becomes friends with her neighbor, a woman in her thirties named Jo.
Katie regularly goes shopping at a store and the owner of the store, Alex, becomes attracted to her. Alex is a widower with two children, Josh and Kristen. Katie becomes instantly attached with the little Kristen, who hasn't started school yet and accompanies her father to the store. One day, Josh almost drowns while fishing, and while Alex rescues him, Katie comforts Kristen. Following this incident, Katie becomes friendlier with Alex, and eventually, she invites him to dinner at her house. They soon come to realize that they love each other, and Alex, who had once been in the army, guesses Katie's secret. Katie, understanding that Alex has come to guess about her secret, reveals it to him, saying that she is married to a man named Kevin. Her real name is Erin. Kevin, who is a policeman, physically abused her, and thus, she was forced to flee from her house, taking a new identity. Alex promises to protect her secret, and soon, their love starts growing deeper.
On the other hand, Kevin is furious at Katie because she has run away from him. He starts searching for Katie, and finally is able to locate where she lives after he comes to know what identity she is using. He arrives in Southport, and sees Katie. That evening, Katie is in Alex's home taking care of the children, as Alex was away from home due to some work. Kevin sets Alex's house on fire, fortunately Katie manages to escape with Josh and Kristen. She has a fight with Kevin, giving the children time to escape. Alex arrives in time and takes the children to Katie's home, and returns to his burning house and attacks Kevin. Kevin escapes from Alex and drives towards Katie's house. After Katie comes to know that Alex left the children in her house, she becomes terrified; she knows Kevin will go to her house to hunt her, and thus the children's lives are in danger. As they reach Katie's house, Kevin attacks Alex with a crowbar. Katie, however, kills Kevin with a gun.
Alex recovers in a hospital and soon, from the remains of the burnt house, a safe is recovered. Alex hands Katie a letter from the safe. Katie goes back to her little cottage and decides to meet her neighbor, friend and supporter, Jo. However, she is shocked to see Jo's house in such a state that gives a hint that the house has never been lived in. Startled, she comes to think that Jo was completely her imagination. Shocked, she starts reading the letter Alex handed her. It is a letter written by Alex's late wife, Carly. And there, it is written that her (Carly's) friends used to call her Jo. Katie realizes that Jo wasn't her imagination, but it was Carly's spirit. She finishes reading the letter, which Carly wrote to the woman with whom her husband would fall in love, requesting the woman, that is, Katie, to always take care of Alex and the children.
Katie starts going to Alex's home, and before leaving her house, she sees Jo's house lighted, and Jo standing and waving her farewell.
