Richard and Keri are a young couple with an infant daughter and are fast growing out of the limited space their cramped one-bedroom apartment affords them. When Keri finds an advertisement in the local paper seeking a live-in couple for meal preparation and light housework in return for room and board they decide to apply and go along to meet the elderly lady who placed the advertisement, finding that the accommodation offered is in a beautiful old mansion. Their interview goes extremely well and there is an instant spark of friendship between them and the elderly lady, MaryAnne Parkin. She offers them the position and they accept.
On moving in, Richard and his brother-in-law are putting some of their furniture on the attic when they come across Christmas box which is ornate and beautiful. They also find old family portraits which turn out to be of Mary's beloved late husband.
Despite the original arrangement with Mary as their employer, the little family are soon having their evening meals with Mary especially when Richard is working late building his new tuxedo rental business and both Keri and their daughter Jenna form a grandmotherly relationship with Mary. She delights in showing them the Bible's that her late husband collected but keeps the most collectible one in her den as it means the most to her.
Richard begins to have strange dreams at night all with the recurring presence of an angel messenger that he does not understand but that makes him uneasy. One night he wakes to hear music in the darkness and follows the sound to where it seems to emanate from - behind the attic door. The music is coming from the Christmas box and he opens it, finding a love letter that he feels compelled to read. He gathers they were written by Mary but does not know their intended recipient.
Meanwhile, the rental shop keeps him ever busier and Jenna is sad that she sees hardly anything of him. She does not understand why he wants to spend more time at the store than he does with her. Mary also chastised him for this and is trying to remind him of the true meaning of Christmas and the importance of family. On December 6 Keri goes to the den as she does every morning but unusually Mary is not there. Keri is drawn to the ornate Bible and sees that the pages have. Even tearstained. This plus Mary's absence leave her feeling very uneasy. When Mary returns she tells them that she was with her doctor who has informed her she has a tumor pushing on her brain and it is inoperable. The main change in her seems to be her growing obsession with Richard's working hours and her anger that he does not see what is important because he is too engrossed inthe store. Keri realizes that Mary is hiding something and that this is making it hard for her to tell Rick what it is that she wants to.
Rick feels that the answer lies in the Christmas Box and gently takes the letter out of it, then goes across the street to see their neighbor Steve, who is close to Mary and has known her all of his life. Steve reveals that Mary had a little girl called Andrea and she places a box like the Christmas Box on the grave which likely contained the letters that she wanted to make sure Andrea would read. Rick realizes that the gift she was giving him was reminding him to cherish Jenna because her childhood was so fleeting that it would be gone in the blink of an eye and the time could not be recreated. He also realizes that the angel in his dreams was Andrea as the stone angel that she represents herself to him as is the stone angel of Andrea's headstone. As he is in the hospital with Mary he thanks her for the gift she has given him and Mary sees Andrea waiting for her; she dies shortly thereafter. Richard realizes that the gift she has given him is the gift of his daughter's childhood.
