In 4th grade, Lily Anderson — who lives in urban Chicago — was given Molly Cumberland — who lives on a farm in Nebraska — as a pen pal. The girls continue to write, even through college, always promising to visit one another. Molly finally makes good on that promise when she shows up at Lily’s door for her 25th birthday party. Lily is thrilled until it becomes clear that Molly has no intention of leaving and wants Lily’s life.