The latest installment of Short Treks will answer a big question Star Trek: Discovery fans won’t even know they had: How did Mr. Saru come to join Starfleet?

Unlike the self-contained two previous Short Treks — “Runaway” and “Calypso” — “The Brightest Star” adds a huge new piece to the ever-expanding canon puzzle of Star Trek. And, because the ending of the short features the appearance of a beloved Starfleet officer, fans might wonder when this all happens, and how it fits in with the upcoming second season of Star Trek: Discovery. Luckily, the writers of “The Brightest Star," Bo Yeon Kim and Erika Lippoldt, have answers.

**SPOILER ALERT: Huge spoilers for Short Treks' “The Brightest Star” follow.**

Because the final moments of “The Brightest Star” depict Saru (Doug Jones) and Georgiou (Michelle Yeoh) meeting for the first time, it begs the question of when exactly this all happened in the future-history of Star Trek. At this point in time, Georgiou is not the captain of the USS Shenzhou, just a lieutenant. So, by the time we get to the era of Discovery, just how long have she and Saru known each other?

The answer it seems is about 18 years.

“Burnham is brought aboard the Shenzhou for the first time in a flashback in 'The Battle of the Binary Stars,' and the events of this short took place about a decade before that,” Lippoldt tells SYFY WIRE. “Saru would have needed time to acclimate to this new worldview outside of his home planet; he's only just learned that humans exist, after all! So he wouldn't have entered [Starfleet] academy right away.”

In terms of Trek chronology, “The Battle at the Binary Stars” happens in the year 2256, and the flashback in which Burnham first beams aboard with Sarek is eight years before, in 2248. So, if “The Brightest Star” is “about a decade” before 2248, then we’re somewhere in the 2230s. For hardcore completists, this means we’re in a decade where Kirk and Spock are little kids, meaning Lt. Georgiou was out contacting alien races with Kirk and Spock literally in diapers!

In another original series connection, in the episode, Saru’s father paraphrases a classic Kirk quote when he says, “If we were meant to go to the stars, we would have wings.” Bo Yeon Kim says this was probably a subconscious reference while she and Lippoldt wrote the script.

"Completely unintentional, and we only realized after the fact. But we do love that it showcases how differently Kelpiens think," Kim says. "While humans did fly because they had to, the Kelpiens dare not think that way."

For Kim, it was also important that “The Brightest Star” tackle the social aspects of the story with a sense of deep realism and sensitivity. “As someone with an anthropology background, it was important to me that we didn’t portray Kelpien society and their belief system as 'primitive' — a low-hanging story fruit when it comes to writing pre-warp alien culture," Kim says. "Erika and I worked very hard to build out the intricate world of Kaminar, which we hope you find alien yet familiar. I found myself referencing the Japanese occupation of Korea quite a bit, in particular, the systematic oppression that occurred over the course of 35 years that ultimately shaped Korea and how Koreans behave today.”

Credit: CBS All Access

Kim’s approach is a time-honored Star Trek tradition: Examine a real-world issue through a science fiction lens while still staying true to the mythology of this fictional future.

In “The Brightest Star,” the philosophical conundrums Georgiou and Saru face are profound, but they’re familiar. Every single version of Star Trek has had its characters face the question of the Prime Directive, the rule that prohibits benevolent Starfleet officers from screwing up the "natural development" of an alien world. In fact, several plot elements of "The Brightest Star" dovetail with the Star Trek: The Next Generation episode "Pen Pals," a fact Kim and Lippoldt were very aware of.

"As we began exploring Saru’s backstory in the writers’ room, 'Pen Pals' did, in fact, come up a lot as it dealt with a pre-warp species," Kim says. "We talked at length (days? weeks?) about the complexity of the Prime Directive, and how each Star Trek series has approached this iconic notion: How do our characters do the right thing, adhering not only to Starfleet’s values but also its governing laws? What are the exceptions, the loopholes?"

Lippoldt adds: "Part of the fun of developing this story is that we've — hopefully —created a scenario that presents a juicy moral quandary. Here, Georgiou made a case to make an exception for Saru based on several factors.

"First, that Saru is the one who initiated contact, and directly asked for help. Second, that during their interaction, Georgiou came to see that Saru displayed an understanding and knowledge of technology. And third, that Saru was only asking for himself. His people, and specifically his father, showed no interest in changing their ways. So by accepting to help Saru leave Kaminar without the rest of his people's knowledge, Georgiou is not, in fact, interfering with the normal development of the planet's civilization."

Even so, this moral quandary leaves Mr. Saru in a situation where he cannot legally return home to visit his people. But will he ever? Does he want to?

"In the first few years of joining Starfleet, Saru had always intended on learning everything he could and returning to Kaminar to help his people," Kim says. "But over the years, he realized that the Prime Directive exists for a reason, and breaking it would bring about serious repercussions, not just to his Starfleet career but to his people. So that is the weight of Saru’s burden."

Will Saru's isolated burden be explored more in Season 2 of Star Trek: Discovery? On this point, Kim and Lippoldt say they have to be "vague." And this vaguery also comes up when the pair are asked about who was Captain of the USS Shenzhou at this point in time, before Georgiou. "Unfortunately, we can't tell you that!" Lippoldt says, which might be suggestive of a definitive answer, one we may or may not learn in Discovery Season 2.

Star Trek: Discovery has had flashbacks illuminate huge plot points since its very first airing. And now that "The Brightest Star" has given so many new layers to Saru and Georgiou's shared past, it shouldn't surprise anyone if part of the bold future of the next season doesn't also dip back into its own past.

Short Treks "The Brightest Star" is streaming now on CBS All Access.