12/12 The Doctor faces the Time Lords in a struggle that will take him to the end of time.
11/12 Trapped in a world unlike any other, the Doctor faces the greatest challenge of his lives.
10/12 The Doctor and Clara find themselves in an alien world, hidden on a street in London.
9/12 Terrifying footage discovered in the wreckage of Le Verrier Space Station.
8/12 With UNIT neutralised, only the Doctor stands in the way of the Zygons.
7/12 The Doctor and friends must try and save Osgood from a rogue gang of Zygons.
6/12 Deadly highwayman 'the Knightmare' and his sidekick come face to face with the Doctor.
5/12 The Doctor and Clara help protect a Viking village from space warriors from the future.
4/12 A fearsome alien warlord sets in motion a twisted plan to ensure his own survival.
3/12 The Doctor and Clara try to help when an underwater base comes under attack.