New York City during the holidays.
Red and Lulu make their nest in a particularly beautiful evergreen tree. It shades them in the hot months and keeps them cozy in the cold months, and once a year the people who live nearby string lights on their tree and sing a special song: O Christmas Tree, O Christmas Tree. But one day, something unthinkable happens, and Red and Lulu are separated. It will take a miracle for them to find each other again. Luckily, it’s just the season for miracles. . . .