Location filming in Vermont was hampered by heavy rainfall. Many exterior scenes were filmed on sets constructed in a local high school gymnasium, but much of the dialogue recorded there was inaudible due to the rainfall on the tin roof, and much post-recording was necessary.
This movie was Sir Alfred Hitchcock's experiment to see how audiences would react to a non-star-driven movie. He was of the opinion that oftentimes having a big star attached actually hindered the narrative flow and style of the story. He also developed the movie to test how American audiences would react to a more subtle brand of black humor than they were used to.
This movie was unavailable for three decades because its rights (together with four other movies of the same period) were bought back by Sir Alfred Hitchcock and left as part of his legacy to his daughter Patricia Hitchcock. They were known for years as the infamous "five lost Hitchcocks" amongst movie buffs. The films were re-released in theaters in 1984 after an approximately thirty year absence. The others are Rope (1948), Rear Window (1954), The Man Who Knew Too Much (1956), and Vertigo (1958).
Alfred Hitchcock: cameo appearance comes around the twenty-one-minute mark, when he's seen walking past the limousine of a man looking at the drawings.