With the holidays just around the corner, Thomas and Percy are determined to deliver the mail to all the people of Sodor. There are presents! The problem is there's a massive whiteout snowstorm covering the entire island and preventing the engines from seeing where they're going. Overcoming various obstacles, Thomas and Percy learn that they can rely on their other senses as well as their familiarity with the island to find where they need to go and deliver the gifts just in time.