The perfect fun for a Christmas special, this is just a wonderfully light and fun story, that is best suited for Christmas. For the first full episode of this Doctor, and the introduction to Ruby, it works so well. This is a highlight story for both of these characters, who give great performances, and a great dynamic throughout this story, which adds to the enjoyment throughout this story. The Goblins might not be the most threatening creatures, but the key here is the Doctor and Ruby, and they sparkle in this episode.