Star Trek TAS: Season 1, Episode Two “Yesteryear”

Stardate: 5373.4 (2269)
Original Air Date: September 15, 1973
Writer: D.C. Fontana
Director: Hal Sutherland       

“Live long and prosper, Sarek of Vulcan.”

Rating: 5 out of 5.

The Enterprise is in orbit around the planet of the time vortex, where the Guardian of Forever resides, the focus of all the timelines in the galaxy which allows people to travel backward in time as previously featured in the TOS Season 1 classic “The City on the Edge of Forever.” Assisting a team of historians who are conducting research into Federation history (including the Aurelian bird-like creature “Aleek-Om” and female named “Grey”), Kirk and Spock (along with historian Erickson) return from the distant past where they witnessed the dawn of Orion, however, suddenly none of the crewmen recognize Spock. Indeed, there is no record of anyone named Spock in Starfleet records, and the first officer of the Enterprise is now Commander Thelin, a member of the “warrior race” of Andorians who has served aboard the Enterprise’s for five years.  

According to Starfleet records, Spock’s father Sarek (a Federation ambassador to 17 planets during his 30-year career) and his mother Amanda (maiden name: Grayson) have gotten divorced following the tragic death of their son Spock, who died at the age of seven during the “kahs-wan,” a traditional survival test for young Vulcan males wherein a Vulcan must survive for ten days in the desert without food, water, or weapons. It was the 20th day of the month of Tasmeen. Since then, Spock’s mother Amanda has also died in a shuttle accident at lunaport while returning to Earth.  

Spock vaguely remembers his kahs-wan as a child, and he recalls a mysterious cousin named Selek who suddenly appeared and rescued him, but then Spock never saw him again. Suddenly, it dawns on Kirk and Spock that Spock must travel backward in time to rescue himself, however, in the time vortex, he must not change the past, or else risk altering the present. Understanding the situation, Spock travels back thirty years in time to the city of Shikahr on Vulcan.  

Here, a young Spock is teased by his schoolmates for being an “earther” and a “terran” because he is half-human and he struggles to perform the Vulcan nerve pinch. Adult Spock plays the part of Selek, a humble cousin of Spock’s who is descended of T’Pel and Sasak, journeying to the family shrine to honor his gods. In a wonderful nod to previously established lore in the TOS Season 2 episode “Journey to Babel,” young Spock has a pet sehlat, a giant “teddy bear” with six-inch fangs. In “yesteryear,” the sehlat’s name is “I-Chaya” (pronounced eye-chigh-yuh).

Together, young Spock and I-Chaya decide to venture out into the desert and to the Llangon mountains to prepare for the kahs-wan, as Spock does not wish to further disappoint his father. However, he is soon attacked by a dragon-esque creature known as a Le-Matya which has poisoned claws, but adult Spock (posing as cousin Selek) comes to his rescue. The Le-Matya strikes I-Chaya and as he lays dying, young Spock seeks a healer in the city to help, but it is too late, the poison has spread too far. It is a touching moment when a young Spock decides to allow his beloved pet to pass away with peace and dignity. The death of I-Chaya is an unnoticed change to the temporal line of events and adult Spock bids a cryptic farewell to his parents, who are slightly suspicious of this mysterious yet familiar figure, and Spock returns to the Enterprise to continue his typical banter with Dr. McCoy.

My Thoughts on “Yesteryear”

Time travel can be a thorny narrative device, however this brilliant installment in TAS from the legendary D.C. Fontana –who also wrote incredible TOS episodes like “Journey to Babel”— offers key character expansion for Spock as a young man. In some respects it reminds me of classic Twilight Zone episodes which tackle the issue of time travel like “Walking Distance” or “A Stop at Willoughby.” “Yesteryear” pays homage to two key TOS episodes, “Journey to Babel” and “The City on the Edge of Forever,” and it does so to masterful effect. If you can look past the truly terrible animation in TAS, the power of this great story expands the backstory and further deepens the allure of the Vulcan mythos.  


Writer Dorothea Catherine “D.C.” Fontana (1939-2019), also worked as a writer for a few different television programs prior to Star Trek, before she briefly worked as Gene Roddenberry’s secretary and then was appointed a writer on the show. At the age of 27, Fontana became the youngest story editor in Hollywood at the time, and she was also one of the few female staff writers. She remained a Star Trek writer until the end of the second season of TOS and she has the notable distinction of being one of the few people to have worked on Star Trek: The Original Series, as well as Star Trek: The Animated SeriesStar Trek: The Next Generation, and Star Trek: Deep Space Nine. Of them all, Deep Space Nine was her favorite series. For TAS, she was appointed story editor and associate producer of the series. This episode was the only one she wrote for TAS.

Star Trek Trivia:

  • This episode has been widely praised by fans as the best of TAS. It was nominated for a Daytime Emmy.
  • NBC was concerned about the issue of pet euthanasia in the episode, however in the end, because he was given full creative control of the series, Gene Roddenberry ruled out over them.
  • Los Angeles stations aired this episode first before “Beyond the Farthest Star” because George Takei was running or office at the time and the studio did not want to risk violating the FCC’s equal-time rule.  
  • Elements of this story have been later incorporated into Enterprise as well as the 2009 Star Trek film.
  • The pet sehlat Spock had as a child, which was mentioned by his mother in the TOS Season 2 episode “Journey to Babel,” is further developed in this episode and is named “I-Chaya.”
  • James Doohan voiced the bird-like Aurelian historian “Aleek-Om,” the historian named Erickson, the Andorian Thelin who was first officer of the Enterprise in the alternative future, and other characters including the voice of the Guardian, Bates, and the Vulcan healer. Majel Barrett voiced the female historian named “Grey” and also Spock’s mother, Amanda Grayson.  
  • Mark Lenard reprised his role as Spock’s father Sarek in this episode.
  • Child actor Billy Simpson performed the voice of young Spock.
  • The desert of “Vulcan’s Forge” is first mentioned in this episode and later appears in the novelized Trekverse.
  • Spock’s mother’s maiden name was first established in this episode, and then later reiterated in Star Trek V: The Final Frontier.  
  • Director Hal Sutherland (1929-2014) directed all episodes of the first season of TAS. He gained early career recognition working on large Disney animation movies before switching to Filmation where he worked on TAS, as well as Flash Gordon, Batman, and Superman animated shows. Notably, pink is a recurring color in TAS. This is because Sutherland was colorblind and thought he was actually selecting the color grey.

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1 thought on “Star Trek TAS: Season 1, Episode Two “Yesteryear”

  1. D C Fontana was a very special writer for the Star Trek universe. I can understand why Deep Space 9 was her favorite Trek series. It certainly had the most specific opportunities that hadn’t been seen in Trek before. Especially for female regular characters like Kira and Dax. I’m glad that she made a most cherished contributed to the animated Trek with Yesteryear. She will be greatly missed.

    Liked by 2 people

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