Revealing mistake: When Victor opens the front door to Mr Foskett and the boys, you can see that the background is actually a painting.
The Affair of the Hollow Lady - S5-E3
Revealing mistake: When Margaret hits the lady, it is very clear she dosen't actually touch her.
The Exterminating Angel - S5-E6
Revealing mistake: The scene with a bee in the Jag is superimposed.
Chosen answer: The episode is 'The Pit and the Pendulum' The first episode of series 4.
James Ransford ★