Some time later, Newton meets a waitress named Gwen Phillips (Goldie Hawn) at a Hungarian restaurant. Believing that she cannot speak English, he spills out his sob story about Becky and the abandoned house. After the restaurant closes, Newton learns that she merely pretended to be Hungarian. They spend some time talking and end up spending the night together.
The next morning, Gwen finds that Newton has left in the middle of the night. However, he unintentionally left behind the drawing of the house he'd built for Becky. Piqued by the drawing, Gwen decides to take a bus ride out to see the house. She is charmed by it, and decides to take up residence in the empty domicile. Needing groceries, Gwen goes to town's convenience store, where charges her groceries to the "Newton Davis" account. When questioned about this, Gwen, who it becomes clear is a natural liar, says that she is Newton's wife.
Gwen meets Becky, and spins a lengthy romantic story about how they fell in love, which impresses Becky. Gwen also meets Newton's parents, who are heartbroken that Newton got "married" without telling them, but Gwen also manages to smooth things over believably with her charm.
One day, Newton travels to his hometown and is shocked to see that his house is lived in. When he finds out what Gwen has done he is initially furious, but he soon sees the potential in her being there. Gwen starts creating all sorts of opportunities for Newton: mending his relationship with his parents, helping out with his career and making Becky jealous. Newton and Gwen come to an agreement in which Gwen will help Newton get Becky, and in return she'll get all the furniture in the house.
Through their time together Newton begins to rely more on Gwen beyond their agreement, and Gwen starts to feel attached to her life with Newton. It is also revealed that Gwen became a compulsive liar in order to escape from what she feels is her own inadequacy, and that she has "changed" her life numerous times.
The film culminates with a reception held at the house in which the sub-plots of Newton's career, family and affections for Becky are brought together. Jealous of Becky, Gwen confronts her in front of everyone, accusing her of trying to win Newton back. Gwen storms out of the house in tears, and Newton follows her, thinking it is still part of the plan. Outside alone, Newton praises Gwen for her brilliance, but Gwen replies that she wanted their marriage to work. Newton watches, confused, as Gwen leaves. Becky takes the opportunity to comfort Newton, and asks him whether all of Gwen's stories were real. Newton answers that they were all true, and chases after Gwen.
Newton stops Gwen as she is about to board a bus to leave town. Although she resists, Newton follows her example and begins telling an outlandish romantic story of something they supposedly did, which makes Gwen decide to stay. The film ends on the note of Newton and Gwen being happily married and living together in the house. The final spoken words are of Newton saying "I love you, Gwen" and Gwen replying, "Actually, it's Jessica."
Blueprints are available through Princeton Plans Press.