Christmas is often associated with special memories, but for some it brings shadows of things that should not have been. Things like unearthly visitors who open their eyes to new worlds and new experiences. Pantomime coats, robot dogs, and a big blue box parked beneath the Christmas tree. Some think these fleeting guests are apparitions, angels, or demons. But all know that Christmas will never be the same again. The Doctor and his companions travel to Christmas past, Christmas present, and those Christmases yet to come. They bring festive laughter and Yuletide joy, creeping dread and screaming horror, slipping in and out of time like the ghosts of Christmas.