During Sodor's Christmas Eve celebration, our favorite engines and vehicles are merrily at work decking the rails, and none more than Percy. While Thomas, Bruno and other engines are decking the rails and preparing their beloved traditions, Percy has finished delivering holiday gifts all over the island...only to discover a child's letter to Santa has got stuck in his cab. Percy is determined to make things right, even if that means tracking down Mr. Claus himself. With help from Thomas and his friends, Percy travels through dazzling parades, sweet-smelling gingerbread bakes and snowflake flurries on a quest to deliver the letter to Santa and make a child's Christmas Wish come true.