When Oscar and Molly rush outside to investigate a massive crash in the night, they're not expecting to find a dazed Angel Gabriel wandering around their grandparents' back garden. And they're certainly not expecting to find themselves in a race against time to save Christmas. But if they don't track down a missing shepherd, wise man, donkey and the actual Mary and Joseph, who've all crash-landed in Chipping Bottom thanks to an angelic mishap, not only will Christmas cease to exist, but they will too. No presents, no crackers, no Christmas dinner -- no Oscar and Molly! Operation Nativity is on.