The original story by Price Day was first published in the April 1958 issue of Alfred Hitchcock's Mystery Magazine. It came to Rod Serling's attention when it was included in the hardcover anthology "Alfred Hitchcock Presents: My Favorites in Suspense" (Random House 1959).
In his prologue, Rod Serling refers to the decision to take action as Oliver Crangle's personal "Gotterdammerung." The German phrase "Gotterdammerung" (translation of Old Norse "Ragnarok") is a Norse myth about a war among various beings and gods, that ultimately results in the burning, immersion in water, and renewal of the world.
Theodore Bikel (Mr. Crangle) was a human- and civil-rights activist who ardently opposed blacklisting and McCarthyism during the 1950s.
The books that Oliver Crangle randomly picks up and pretends to carefully read while avoiding Mrs. Lucas' questions are the September 1961 edition of the Official Airline Guide (OAG) North American flight guide, and US Army Technical Manual TM 9-372, which describes the M2 90mm anti-aircraft cannon.