Scott Calvin has been Santa Claus for the past eight years, and his loyal elves consider him the best Santa ever. But Santa's world is turned upside down when he's dealt a double whammy of bad news: not only has his son, Charlie, landed on this year's "naughty" list, but if Scott doesn't marry by Christmas Eve "just a month away!" he'll stop being Santa forever. (It's right in his contract -- the "Mrs. Clause") Desperate, Scott turns to the elves' new invention -- a machine that can replicate anything -- to create Santa II (a toy version of himself) and he leaves his double in charge. Things quickly go south at the North Pole when Santa II institutes some strange redefinitions of what's naughty and nice; worse, when Scott finally falls for a potential Mrs. Claus, she threatens to drive a wedge between him and Charlie. In a climactic battle pitting Santa, Charlie, the new Mrs. Claus, and the elves against Santa II and his army of tin soldiers, the future of Scott's family, the North Pole, and Christmas itself, hangs in the balance.