6/8/1947
There's a little house on stilts at the top of Mt. Wilson, protected by a barbed wire fence. There's a sign on the fence that reads "the public is forbidden to pass beyond this fence under severe penalty." It doesn't state exactly what the severe penalty is, or who or what will administer it. Three men ignore the warning and proceed to find out.
Like many Quiet, Please episodes, "Nothing Behind the Door" provides a good preview of the unique style and goals of Cooper and Chappell.
