When divorced dad Scott Calvin goes to sleep on Christmas Eve with his son Charlie who is eagerly awaiting the arrival of Santa Claus, Scott breaks to Charlie the news that Santa is not real. When they hear the noise of Santa landing on thier roof, they both run outside where Scott sees Santa on the roof of thier house. Then, believing he is an intruder, he shouts at him to get off of the roof. Santa gets startled and slides off of the roof and gets killed upon hitting the ground where his body vanishes. Scott then humors Charlie by putting the suit on and climbing in the sleigh. However, Santa's eight reindeer take off with Scott and Charlie in the sleigh and Scott delivers the rest of the world's presents. Afterwards the reindeer take him to the North Pole where Scott meets up with Santa's elves who tell him that when the current Santa dies, the next person to put on the suit becomes the next Santa. Scott finds that an improbable statement and returns to his normal life, but over the next year, he begins to transform into Santa. He still finds it unbelievable and does not stop doubting it until next Christmas when kids are telling him what they want for Christmas and he gets the presents to be delivered from the elves. Scott finally learns to accept the fact he is Santa Claus after he sees how happy Charlie becomes, but doing so makes him a figure of outcast with the rest of Charlie's family whose mother and family psychologist want him locked up.