It's Only the Ending which is painful. Otherwise,I would have rated it a "10." So as it stands, I have to truthfully rate it a "9."
James Corry as played by actor Jack Warden gives such a realistic portrait of loneliness that after all that BUILD-UP, I was expecting the female Robot to be actually sentient with actual emotions. But as it turned out, that was Not the case, as She turns out to be a soul-less machine. That's why the ending shocked me so much and even left me aghast. The way it affected me, it was as though Corry's friend killed an actual human-being! Yes, PAINFUL to watch, but its realistic depiction of Loneliness makes me view the episode over and over. Only Rod Serling could manipulate my emotions the way he did.