Spoilers: Post The End of Time, non-canon
Characters: The 11th Doctor, (Cumberbatch)Master with Sherlock mannerism, Donna Noble, Clara Oswald
Synopsis: Rassilon has risen and the 10th Doctor is dead. Donna discovers that River Song has hidden an old enemy in her past, while in another dimension, the 11th Doctor is haunted by a ghost from his childhood who is trapped inside a nightmare mirror reality of torture and insanity.
The Master's unrelenting thirst for revenge has unintentionally revived Rassilon and has caused the 10th Doctor's death. Aware that the Doctor was protecting the Master for a reason, and guided by the prophecy of the Oods, River Song eventually spared the Master's life, although he still was made to pay a very heavy price.