When a disgruntled elf takes over the North Pole, she turns time backwards and Santa Claus begins getting younger fast. It's up to a loyal elf, a little girl with a magic key, and the now-teenage Santa to save the future of Christmas.

It's the close of World War II. Unwilling to surrender, rogue German forces shoot down a returning British squadron leaving Sydney Baker wounded and lost with the enemy closing in. He's saved by American soldier and the duo must face their fears, both internal and external, to defeat the enemy and make it back to friendly territory alive.