It's Christmas Eve and Nan receives some unexpected visitors, in the form of Ghosts of Christmas Past, Present and Future. In this comic retelling of Dickens' A Christmas Carol, Nan is shown the error of her ways, but is it too late for her to swap her Scrooge-like misery for some seasonal goodwill? Mathew Horne returns as Nan's ever-patient grandson Jamie, and there are guest appearances from David Tennant, Ben Miller and Roger Lloyd-Pack.