While Santa’s mind is fixed on training Christopher, Mrs. Claus, daughter, Kristy, and Christopher are determined to find a way to tell Santa the obvious – which he seems to be stubbornly ignoring – that Christopher is unsuitable for the job. The family is keeping Christopher’s secret and it will only be sprung on Santa on Christmas Eve. Meanwhile Kristy, just ten years old, feels she is up to the task of taking Santa’s place.

Christmas Eve finds Santa and his trainee taking off for high flying adventures around the world, including natural disasters – angry dogs, cracking ice – and some disasters not so natural – smoking chimneys, frightening encounters with jets. When Santa discovers his family has tricked him, he nearly turns the sleigh around, to end the flight. Christopher and Kristy have to impress their father with their talents. Kristy especially has to believe in herself enough to convince Santa that, working together, they just might be able to save Christmas.