In this hugely anticipated follow-up to the record breaking Doctor Who 50th Anniversary Special, we bid adieu to Eleventh Doctor Matt Smith and welcome Peter Capaldi (The Thick of It, The Hour) in his first televised appearance as the new Doctor. 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. This landmark episode is bound to be a thrilling adventure for the ages.