The BBC Media Centre has released the official synopsis of the Doctor Who 50th anniversary special:
THE DAY OF THE DOCTOR - by Steven Moffat
The Doctors embark on their greatest adventure in this 50th anniversary special. In 2013, something terrible is awakening in London’s National Gallery; in 1562, a murderous plot is afoot in Elizabethan England; and somewhere in space an ancient battle reaches its devastating conclusion. All of reality is at stake as the Doctor’s own dangerous past comes back to haunt him.
Doctor Who: The Day of the Doctor will broadcast on Saturday 23rd November on BBC One, BBC One HD and select cinemas worldwide, a time is yet to be confirmed.