This hour-long Christmas special of the relaunched sci-fi adventure series is loosely based on Charles Dickens' festive tale 'A Christmas Carol'. Matt Smith stars as the legendary Time Lord, who must save Amy (Karen Gillan) and Rory (Arthur Darvill) when they become trapped aboard a spaceship that is about to crash. The only way the Doctor can rescue them is to save the soul of lonely old miser Kazran Sardick (Michael Gambon), the richest man in Sardicktown. Opera singer Katherine Jenkins makes a special guest appearance.