On Christmas Eve, divorced dad Scott Calvin and his son discover Santa Claus has fallen off their roof. When Scott takes the reins of the magical sleigh, he finds he is now the new Santa, and must convince a world of disbelievers, including himself.

Four grade school girls witness a classmate murdered by Milo Jeeder, a little boy in a yellow raincoat, before he supposedly drowns to death in a river, only to discover sixteen years later that Milo has seemingly reappeared, unchanged.