Sunday 14th September 7.30pm
The Doctor is trapped, alone, powerless and terrified, on the leisure planet Midnight. Soon, the knocking on the wall begins.
Only a woman called Sky seems to know the truth – but as paranoia turns into a witch-hunt, Sky turns the Doctor’s greatest strengths against him, and a sacrifice must be made.
David Troughton, who guest-stars in this episode, is the son of Patrick Troughton who played the Second Doctor Who.