The chapter in question is called “The Trade-Ins,” and it explores the idea of mortality through the perspective of an elderly couple who are still deeply in love. Thanks to a new innovative technology, the couple, John and Marie Holt (Joseph Schildkraut and Alma Platt), are given the opportunity to trade in their failing bodies for younger, newer models. The couple can only afford to have one of them undergo the procedure, and John is made young again. Though he plans to raise money so Marie can follow suit, his youthfulness brings her to tears, so he decides to “return” the younger body. In the end, the pair decide to face old age and death naturally, hand in hand with the one they love most.
Though “The Trade-Ins” certainly has some logic holes, it’s an especially emotional episode of the series, and according to Marc Scott Zicree’s book “The Twilight Zone Companion,” there was an unexpectedly heartbreaking reason it hit so hard. As episode director Elliot Silverstein later recalled, Schildkraut’s own wife was in the last days of her life during shooting. “He was undergoing a tragedy at the time,” Silverstein shared. “His own wife was dying.” The cast and crew apparently weren’t aware of the extent of her illness at the time, but the filmmaker says Schildkraut’s second wife, Marie McKay, passed away in the middle of the three-day shoot. McKay died in February 1962, and the episode would air in April of the same year.