Each December, Holly writes to a stranger who is also spending Christmas alone and receives a letter from another lonely person in return. Usually, the letters go unanswered. But this year, the letter Holly receives is different; not only is the letter full of a grief she knows all too well, but its writer, Emma, mentions a place that Holly has visited. When she realizes she might actually be able to find the letter's author, Holly becomes determined to reunite Emma and her estranged grandson, Jack, with whom she is desparate to reconnect. She realizes she's met Jack once before...and the connection was electric. Holly is determined; if she can fix Emma's family, she might also be able to fix her own. Though as it turns out, Holly might have less time to put things right than she thought...