All Our Yesterdays (Star Trek: The Original Series)
"All Our Yesterdays" is the twenty-third and penultimate episode of the of the American science fiction television series "". Written by Jean Lisette Aroeste and directed by Marvin Chomsky, it was first broadcast March 14, 1969. In the episode, Captain Kirk, Spock and Dr. McCoy are trapped in two timeframes of another planet's past. It guest-stars Mariette Hartley as Zarabeth and Ian Wolfe as Mr. Atoz. The title comes from a soliloquy given by Macbeth. Plot. The Federation starship "Enterprise" arrives at the planet Sarpeidon, whose star is soon to  go nova. Surprised to find the surface devoid of humanoid life, Kirk, Dr. McCoy and Spock beam down to investigate. They encounter one last remaining resident, a librarian named Mr. Atoz. Aware of the imminent destruction, Atoz tells the landing party that he will soon escape to rejoin his family. Atoz shows them the Atavachron, a machine with a time portal. They hear a woman scream. Kirk instinctively runs through the portal and McCoy and Spock follow. Atoz tries to warn them that they were not "prepared." Kirk finds himself in a period similar to 17th century England while McCoy  and Spock travel back 5,000 years to Sarpeidon's ice age. They cannot locate the portal, but the three are able to speak to each other. Spock surmises that the Sarpeidons have all escaped to their planet's past. The woman who screamed is a thief, and the policemen who come to arrest her hear Kirk speaking to his friends and suspect him of being a witch. In the jail, Kirk mentions the Atavachron to the interrogating prosecutor. This startles him, and Kirk suspects he is also from the future. Kirk escapes his cell by luring his jailer close  and overpowering him. The prosecutor confirms his suspicions but explains that returning to the future would be fatal, since the time travel preparation involves changes to the traveler's biology. Kirk tells him that he went through no such preparation. The prosecutor informs him that an "unprepared" person cannot survive in the past for more than a few hours, just as a "prepared" person cannot survive in the present. The prosecutor leads Kirk to the portal, and Kirk returns to the present. McCoy and Spock are saved by Zarabeth, a woman who takes them to a sheltering cave . Upon arrival in the past, Spock begins displaying uncharacteristic emotionalism: He continues carrying McCoy when logic would dictate he abandon him, he falls in love with Zarabeth, and he reacts with anger at McCoy's racial slurs. As McCoy recovers from severe exposure, Zarabeth explains to Spock that she too is from Sarpeidon's future, but a tyrant banished her to this era, in which she is the only extant humanoid. She also explains that the Atavachron is a one-way trip. Spock accepts this and becomes increasingly hostile to McCoy's continued desire to return to the present. McCoy  accuses Zarabeth of lying about their inability to return because she is desperate not to be abandoned to unending loneliness again, and says that Spock backs her out of emotional attachment. McCoy realizes that being brought 5,000 years into the past is causing Spock to revert to the barbarism of the ancient Vulcans. Realizing the emotionalism of his behavior, Spock asks Zarabeth again about the portal. She admits she doesn't know what the effect of a return trip will be on him and McCoy. Back in the library, despite Kirk's explaining that they are not from Sarpeidon, Atoz  stuns him and tries to force him back into the portal. Kirk awakens, overpowers Atoz and forces him to help find McCoy and Spock. Eventually Kirk is able to talk with the two. Unwilling to leave Zarabeth, and still unaware that he will die soon if he remains in the past, Spock tries to send McCoy through the portal alone. However, because McCoy and Spock went through the portal together, neither one can go back without the other. Upon their return, Atoz hurries through the portal to his chosen era. Spock reverts to his normal self, and with little time  to spare they are beamed back to the "Enterprise". Reception. In 2015, SyFy ranked this episode as one of the top ten essential "Star Trek" original series Spock episodes. In 2016, "The Hollywood Reporter" rated "All Our Yesterdays" the 39th best episode of all "Star Trek" episodes. In 2016, SyFy ranked "All Our Yesterdays" as the 12th best time-travel plot of all episodes of the "Star Trek" franchise. They point out the episode offered fresh perspective on time travel by exploring the past of an alien world, as well as an interesting exploration of the characters Kirk, Spock, and  McCoy. A 2018 "Star Trek" binge-watching guide by "Den of Geek", recommended this episode for featuring the trio of characters Kirk, Spock, and Bones of the original series. In 2019, "Nerdist News" included this episode on their "Best of Spock" binge-watching guide. They also ranked it the tenth best time travel episode of the "Star Trek" franchise, including the later 750+ episodes. They note this episode for featuring Spock's travels to an ancient ice age of an alien world, and at that time his emotions are triggered by a woman and the effects of time travel . In the series, they remarked that normally the character does not have much emotion, so seeing the character deal with emotions provides a change of pace for the character's presentation. Sequels. Author Ann C. Crispin wrote two non-canon novel sequels to this episode, titled "Yesterday's Son", and "Time for Yesterday". Releases. "All Our Yesterdays" and "The Savage Curtain" were released on LaserDisc in the United States in 1985. This episode was released in Japan on December 21, 1993 as part of the complete season 3 LaserDisc set, "Star Trek: Original Series log.3". A trailer for this and  the other episodes was also included, and the episode had English and Japanese audio tracks. The cover script was スター・トレック TVサードシーズン This episode was included in TOS Season 3 remastered DVD box set, with the remastered version of this episode.