Dean Stockwell had to drop out of The Purple Testament (1960) due to scheduling conflicts. Two years later, he starred in this episode. Both stories are about American soldiers who have supernatural visions during the Pacific War in 1945, and both have William Shakespeare quotes as titles.
The title refers to a quote from William Shakespeare's play 'The Merchant of Venice': "The quality of mercy is not strain'd, It droppeth as the gentle rain from heaven."
This episode was one of four episodes to be remade for Twilight Zone: The Movie (1983), though only loosely remade in this instance. The relevant segment was directed by John Landis.
This episode takes place on August 6, 1945 and May 4, 1942.
Dean Stockwell's Lt. Katell was supernaturally placed in another person in another time. Stockwell's later series Quantum Leap (1989) was about a character who jumps into the lives of other people.