New Doctor Who Christmas Special Trailer Released Online

As part of the BBC's ongoing Doctor Who Adventure Calendar countdown, the network has released a new trailer for the 2014 Doctor Who Christmas Special.

The trailer shows the Doctor (Peter Capaldi) encountering what seems to be some hostile aliens at the North Pole. Naturally, he calls in Santa Claus (Nick Frost) for help.

Even creepier is the message that Clara (Jenna Coleman) seems to be receiving from a black board that she keeps trying to erase.

See for yourself in the trailer below:

The 2014 Doctor Who Christmas Special, "Last Christmas," airs Christmas Day on BBC One and BBC America.