THE TIME OF THE DOCTOR
The synopsis of the episode has also been revealed:
THE TIME OF THE DOCTOR - by Steven Moffat
Orbiting a quiet backwater planet, the massed forces of the universe’s deadliest species gather, drawn to a mysterious message that echoes out to the stars. And amongst them - the Doctor. Rescuing Clara from a family Christmas dinner, the Time Lord and his best friend must learn what this enigmatic signal means for his own fate and that of the universe.
Doctor Who: The Time of the Doctor, the last to feature Matt Smith as the Doctor, is set to air this Christmas on BBC One and BBC One HD, a time is yet to be confirmed.