How can Santa deliver billions of presents to the whole world in just one night? With an army of one million combat-style Field Elves and a vast, state-of-the-art control centre under the ice of the North Pole! So how could this incredible operation have missed one child? To Santa's young son, Arthur, it threatens to end the magic of Christmas. With retired Grandsanta, a rebellious young elf, an old sleigh and some untrained reindeer, Arthur sets out on a crazy mission to deliver the last present!