Lauren Cooper (Catherine Tate) is David Tennant's nightmare student!

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.

Catherine Tate comes bearing gifts in the shape of some favourite comedy characters in her 2007 Christmas special. Bernie the nurse invites a famous patient to the karaoke party, Lauren spits some lyrics and learns to kayak, whilst Nan invites her daughter and new boyfriend over for Christmas dinner.