Olive is merrily preparing for Christmas when suddenly she realizes "Olive... the other Reindeer... I thought I was a dog. Hmmm, I must be a Reindeer!" So she quickly hops aboard the polar express and heads to the North Pole. And while Santa and the other reindeer are a bit surprised that a dog wants to join their team, in the end, Olive and her unusual reindeer skills are just what Santa and his veteran reindeer team need.