Jodie Whittaker is back for the final episode in the current series, which is not airing on Christmas Day for once (Shock, horror! – apparently).
The Doctor and her companions arrive back at the present day, as New Year arrives. However, they also begin to uncover an archaeological mystery that seems to stir a terrible evil that has spanned centuries, and now may well destroy the world.
Doctor Who is on BBC One at 19.00.