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.

Clara is summoned to an impossible conference call, alerting her that the deadly Whisper Men are closing in on Vastra, Jenny and Strax. Someone is kidnapping the Doctor’s friends, leading him toward the one place in all of time and space that he should never go. It’s a deadly trap that threatens to unravel his past, present and future...