"Winter is coming," warns this stateside trailer for the Doctor Who Christmas special (winter is already here, if you ask us!) and that means snow, Snowmen (no, not the kind that take you walking in the air) and what we're pretty sure is the voice of Ian McKellen, telling us "There is danger here".

He's not wrong – just look at those Snowmen's teeth...

Doctor Who Christmas special The Snowmen is on Christmas Day at 5:15pm on BBC1