From archived tv.com site: episode is based on the short story "Water's Edge" by Robert Bloch. The story was first published in Mike Shayne Mystery Magazine (September, 1956).

From archived tv.com:  episode is based on the short story "The Return of Verge Likens" by Davis Grubb. The story was first published in Colliers (July 15, 1950).

From archived tv.com trivia: This episode was original scheduled to air on November 22, 1963. It was preempted as was all originally scheduled programming, due to network coverage of the assassination of President John F. Kennedy.

From archived TV.com trivia: "The Damnation of Faust" is the record Isabel is listening too when Martha asks her if it's a new purchase.