The Unicorn and the Wasp - S4-E7
Factual error: The hotel in Harrogate was not called the Harrogate Hotel as shown in the episode; it was called the Swan Hydropathic Hotel.
The Unicorn and the Wasp - S4-E7
Factual error: In Lady Edison's flashback, she's reading "The Murder Of Roger Ackroyd", her favorite book. However, this episode is set in 1926, and the dust cover is from 2006.
The Unicorn and the Wasp - S4-E7
Factual error: In real life, Agatha Christie's famous disappearance occurred in December 1926. This episode is quite plainly not set in winter, what with the outdoor garden party and lush green foliage.
Chosen answer: The Master knows that deep down, he deserves death for the crimes that he's committed throughout his life, and since he regards The Doctor as his arch-foe, he expects it to be at his hands. The fact that The Doctor is still willing to forgive him for all of his crimes hurts him more deeply than death would.
Captain Defenestrator