Lower Decks Just Retconned Xon, Star Trek’s ’70s Faux-Spock

This article contains spoilers for Star Trek: Lower Decks Episode 9.

Lower Decks has made its most obscure Star Trek joke yet. Unquestionably, when Mariner drops the name “Xon” in Star Trek: Lower Decks Episode 9, “Crisis Point,” only a fraction of the Trekkie population will truly get it. And that’s okay because this joke not only cuts deep, but it also might have brought a very specific Vulcan back from pseudo-canon purgatory. Want to know who the hell Xon is and why Mariner referenced him in connection with a fake Star Trek movie? Read on!

When Mariner tells Boimler that she didn’t think he was going to “make the final cut’ of her holodeck movie, she points out that she considered his role in the movie as “kind of a Xon.” When Boimler says “Who’s Xon?” Mariner responds, “Exactly!”

Yes, that’s right. A lot of Trekkies have never heard of Xon, and that’s for a very good reason: Xon is a Star Trek character who never actually appeared in a Star Trek movie or TV series, but, at one point, he very much was going to be a major character in a rebooted Trek TV series called Star Trek: Phase II. This character was real enough to have been cast, too. If you look around the internet, you can even find photos of Xon rocking a gold TOS command uniform. He’s a Vulcan with a feathery, dreamy ‘70s haircut that feels closer to Apollo from the 1978 Battlestar Galactica or your boy Luke Skywalker in A New Hope. Although Xon was a Vulcan, he was definitely not Spock.

But why Xon? Or more importantly how Xon? The answer is pretty easy. In 1977, Paramount, Gene Roddenberry, and most of the TOS cast were in the planning stages of doing a TV series generally known as Star Trek II or Star Trek: Phase II. This sequel series would have been set aboard the refit USS Enterprise, under the command of Captain James T. Kirk, but with no Spock. Leonard Nimoy declined to be in the series for various reasons. In his second memoir, I Am Spock, Nimoy says that Spock’s role on the show felt more like a few cameos. In that book, Nimoy theorized that it was possible he was being offered a diminished role because his first book, I Am Not Spock, gave everyone the impression he didn’t really want to be associated with the role anymore. He also felt like it was kind of an insult. Either way, he said no. And so, Roddenberry cooked-up a Spock replacement: Xon.

Xon was to be played by actor David Gautreaux, who did several screen tests in costume, and in full Vulcan makeup. Unlike Spock, who was all about repressing his emotions, the idea behind Xon was that he’d be more curious about human emotions because he was fully Vulcan. In this way, Xon predicted the story arcs for Data, Seven of Nine, and T’Pol. But, of course, Xon himself never actually appeared in any version of Star Trek on screen. When Phase II was transformed into Star Trek: The Motion Picture, Leonard Nimoy agreed to return as Spock and the character of Xon was eliminated. David Gautreaux was given a small role as a human officer named Commander Branch, who, in the movie, is the guy at Epsilon station giving Starfleet intel about V’Ger. You might remember him as the guy who said the oh-so-famous line, “That’s in Klingon boundaries. Who are they fighting?” Yes, this is the person who nearly replaced Spock. That’s Xon.

So, outside of a funny reference, does Lower Decks actually add anything to the story of Xon? Well, maybe! If we consider Lower Decks to be canon — which is pretty easy to do — then how does Mariner know who Xon is? The simple answer is that, at some point in Starfleet history, Xon was a real person. A directory placard in the Starfleet Academy set in The Wrath of Khan lists the offices for a Captain Xon, which seems to indicate that, even before Lower Decks, Xon was canon, but in the background. This episode of Lower Decks is the first time his name is spoken. We already know Mariner is something of a history nerd when it comes to Starfleet’s colorful past, so it’s possible that she does know who Xon is, and that his Starfleet career is super interesting.

Or. Mariner is aware that Xon was once bound for greatness, but for whatever reason, didn’t make the final cut of his own life. Either way, if Lower Decks decides to bring Xon out in the flesh, it will be a homecoming for a forgotten Vulcan, 41 years later. Clearly, in cultural memory, Xon has lived long. Whether he’s prospered is up for debate.

Star Trek: Lower Decks airs its season finale next Thursday on October 8 on CBS All Access.