The BBC have released this synopsis for this years Christmas special 'A Christmas Carol'
Amy and Rory are trapped on a crashing space liner, and the only way The Doctor can rescue them is to save the soul of a lonely old miser, in a festive edition of the time-travelling adventure, written by Steven Moffat. But is Kazran Sardick, the richest man in Sardicktown, beyond redemption? And what is lurking in the fogs of Christmas Eve?