Revealing mistake: The solid brick wall bends like vinyl when Colonel Malloy touches it.
Night Gallery (1970)
1 revealing mistake in A Question of Fear - chronological order
Starring: Joanna Pettet, Rod Serling, Larry Watson, Matt Pelto
The Cemetery - S1-E1
Continuity mistake: From the inside view of the window the Hendricks gravestone and the family name is visible on it. From the outside view of the window the gravestone and the Hendricks are facing away from the window.
Rod Serling: For those of you who've never met me, you might call me the under-nourished Alfred Hitchcock.
Trivia: The scene of the spooky castle on the rocky shore was used in episodes of "Gilligan's Island" featuring Vito Scotti as mad scientist Boris Balinkoff.