Jamie (Hynes) hasn't told his family that he and his now ex-girlfriend Emily (Lenz) broke up. After an inopportune run-in with Emily at the train station in his hometown, Jamie convinces her to pretend they're still a couple to avoid ruining Christmas for his family. Jamie and Emily engage in a week-long ruse of engaging in his family's holiday activities together. While they're stuck in his family's home together, the pair discovers their relationship might still have some potential, resulting in a very unexpected Christmas.
Emily works at an ad agency and is sent to her ex's hometown before Christmas. She arrives at the train station as her ex is picked up by his family. They mistakenly think Emily's still an item.