Setting aside that it launched a popular franchise, Star Trek: The Original Series remains an enjoyable watch on its own. Episodes like “The City on the Edge of Forever,” “Balance of Terror,” and “Mirror, Mirror” are still well regarded decades later, and the series’ standing within the sci-fi genre and influence on pop culture can’t be understated.

All that being said, there are some episodes that don’t properly reflect Star Trek: The Original Series being one of the best sci-fi TV shows. Among them is the season 2 finale, titled “Assignment: Earth.” Originally airing on March 29, 1968, the episode saw the crew of the USS Enterprise traveling back in time to the same year and encountering a mysterious man with advanced technology named Gary Seven, played by Robert Lansing.

As far as its overall quality goes, “Assignment: Earth” is by no means terrible. However, as a Star Trek episode, it fails to measure up. The story and its origins make for one of the weirdest entries in this three-season show, and the franchise would be better off by deeming it non-canon.

“Assignment: Earth” Wasn’t Supposed To Be A Star Trek Episode

“Assignment: Earth” was originally conceived by Star Trek creator Gene Roddenberry as a pilot for a separate TV show. In this earlier incarnation, Gary Seven hailed from the 24th century and was the only human to survive being sent back in time. His mission was to prevent the shapeshifting aliens known as the Omegans from changing Earth’s history in 1968 so they could defeat humanity in the 24th century.

After writing the pilot script, Roddenberry came up with a series pitch for Assignment: Earth with Art Wallace. When no network picked up the pilot, Roddenberry reworked the story so that it would not only fit within Star Trek: The Original Series but also function as a backdoor pilot for a spinoff. However, that didn’t move forward either, making the “Assignment: Earth” episode just another standalone tale in the Enterprise’s five-year mission.

“Assignment: Earth” Sits Awkwardly Against Star Trek Canon

Paramount

In terms of the placement of “Assignment: Earth” within Star Trek’s canon, it’s not the greatest fit. This largely stems from the circumstances in which the Enterprise ended up in 1968, as well as the vague details surrounding why Gary Seven was tasked with preventing the McKinley Rocket Base from launching an orbital nuclear weapons platform.

For one thing, time travel was treated like it’s no big deal in the episode. Captain James T. Kirk narrated at the beginning of the episode that the Enterprise used the “light-speed breakaway factor” to go back to the 20th century and conduct a research mission about how Earth “survived desperate problems in 1968.” From the way he was talking, it sounded like this was an easy feat to pull off.

However, that was the only instance where time travel was accomplished so seamlessly. This specific method, also known as the “slingshot effect,” had previously been used in “Tomorrow is Yesterday,” and was later utilized in Star Trek IV: The Voyage Home and the Star Trek: Picard episode “Assimilation.” Doing so was incredibly difficult and posed great danger. It doesn’t make sense that the Enterprise did all that just to monitor 1968 based on sketchy historical details.

Granted, there’s a history of Kirk breaking the Temporal Directive, but at the end of “Assignment: Earth,” he and Spock deduced that the Enterprise was always supposed to interfere with the weapons launch. So, this was a self-fulfilling mission for the Enterprise crew, which is fine enough, but then there’s the issue of Gary Seven’s background.

It’s never revealed in this episode who he and his colleagues, Agents 201 and 347, were working for, nor any information on why these enigmatic individuals are so invested in Earth, or how they knew with absolute certainty that the weapons platform needed to be destroyed. This information wouldn’t be provided until the Star Trek: Prodigy two-parter “The Devourer of All Things,” which was released in 2024. Wesley Crusher identified Seven and his colleagues as agents of the Travelers.

More bizarre of all, however, was Gary’s cat, Isis. She communicated with him telepathically and was able to take on a human form, with no explanation of how these feats were possible. Nearly 60 years later, Isis’ origins remain a mystery.

“Assignment: Earth” Is Far From Star Trek: The Original Series’ Greatest Moment

Paramount

Gary Seven and Teri Garr’s Roberta Lincoln, the secretary who got caught up in the events of “Assignment: Earth,” were later explored in novels and comic books. Nevertheless, this episode was a strange blip in Star Trek: The Original Series’ run. Even accounting for how TV show episodes from that era were filmed to be standalone so that anyone could easily follow along, it still felt too tonally disjointed from the larger Original Series framework.

It would have been better if Gene Roddenberry’s original vision for Assignment: Earth had been realized, because as a separate TV show, it has an intriguing premise. With enough support, such a series too could have run for multiple seasons, if not performed even better than Star Trek: The Original Series was airing on NBC. Maybe Assignment: Earth would have launched its own franchise as well.

That’s not what happened, so instead, it would be better if the Star Trek franchise considered not counting what happened in “Assignment: Earth” as part of the official canon. There’s already no shortage of continuity issues throughout the many Star Trek TV shows and movies, not to mention plot threads that were set up, but never followed up on. It wouldn’t be too much of a stretch to wipe this story away.

“Assignment: Earth” is far from worthy of being considered one of the best Star Trek: The Original Series episodes. As such, fans are better off not factoring its events into the franchise’s narrative tapestry. It was a misfire that should have been an unconnected story like Roddenberry wanted. Maybe then it would have earned a more positive reception.

Release Date

1966 – 1969-00-00

Showrunner

Gene Roddenberry

Directors

Marc Daniels, Joseph Pevney, Ralph Senensky, Vincent McEveety, Herb Wallerstein, Jud Taylor, Marvin J. Chomsky, David Alexander, Gerd Oswald, Herschel Daugherty, James Goldstone, Robert Butler, Anton Leader, Gene Nelson, Harvey Hart, Herbert Kenwith, James Komack, John Erman, John Newland, Joseph Sargent, Lawrence Dobkin, Leo Penn, Michael O’Herlihy, Murray Golden

Writers

D.C. Fontana, Jerome Bixby, Arthur Heinemann, David Gerrold, Jerry Sohl, Oliver Crawford, Robert Bloch, David P. Harmon, Don Ingalls, Paul Schneider, Shimon Wincelberg, Steven W. Carabatsos, Theodore Sturgeon, Jean Lisette Aroeste, Art Wallace, Adrian Spies, Barry Trivers, Don Mankiewicz, Edward J. Lakso, Fredric Brown, George Clayton Johnson, George F. Slavin, Gilbert Ralston, Harlan Ellison