On the surface, “The Sanctuary” is pretty easy to dismiss as a standard, middle-of-the-road Star Trek: Discovery episode. It checks quite a few boxes inside the framework of a standalone Federation mission to a new world, accompanied by requisite space battles, fisticuffs and character beats.

But this weeks’ entry could end up being one of the most importantly-connective chapters of the season, as more than half a dozen characters take significant steps in their journey to figuring out where they belong in the 32nd century. And solving those feelings of detachment, identity and purpose is the central core of this very strong season of Discovery.

Coming off the heels of “Unification III,” which solidly focused on Michael Burnham’s journey to find her own direction in this far future, “The Sanctuary” turns its sights on a host of additional personalities working to figure out their place, as Book, Adira, Georgiou, Saru, Tilly, and even Detmer get significant time and scenes to evolve their characters.

The best of these narrative arcs continues to be the introduction of Cleveland “Book” Booker (David Ajala) to the series, and the story here focuses on a return to his homeworld of Kwejian. The planet, unfortunately, has entered into a submissive long-term partnership with the Emerald Chain — this season’s bad guys — to help alleviate a problem with sea locusts affecting their food supply.

The locusts are wondrously visualized here through the combined talents of creature designer Neville Page, VFX supervisor Jason Zimmerman, and composer Jeff Russo; it’s an amazing visual effect that helps present the world to both Burnham and the viewer.

In reconnecting with his “brother” Kyheem (Ache Hernandez), we learn that the oft-mentioned leader of the faction, Osyraa, is basically running a protection racket with the Emerald Chain and using her leverage, in this case, to lure Book back to his home planet. Her goal is to get him into her possession so that she can get to Discovery, which is harboring Ryn — Book’s Andorian friend from “Scavengers” — who has a secret that she doesn’t want getting out.

Despite the convolution of those plot mechanics, the scenes on the surface of Kwejian are mostly very good. In addition to learning that Book’s real name is “Tareckx,” we get to see him use his ethereal powers to communicate with the locusts and confront Kyheem for the bad deal he made with the Orion leader of the Emerald Chain, Osyraa (Janet Kidder).

“What happens when they come for you? Who is going to stand for you?” he tells his brother, who — after some prerequisite fisticuffs — finally sees the error of his ways.

The two old friends eventually reunite to use their powers to get the locusts to return to the sea, thanks to an assist from Discovery, amplifying their electromagnetic connection from orbit. But consistent with what we’ve seen from the fascinating new cast member, Book stresses that all he can do is ask if they will return, he won’t force them. “It’s their choice,” he says.

When it’s all said and done, Book drops a surprising bombshell: he has come to realize, through his strengthening bond with Burnham, that the Federation is doing the same work he’s been focused on: helping those in need…. and now he wants in. A surprising revelation for the vagabond character with a cat named Grudge.

Meanwhile, Discovery’s presence in orbit over Kwejian has been deemed by Starfleet as an “observational only” mission, so when Osyraa shows up, Captain Saru (Doug Jones) must balance the situation delicately. Thankfully, he has his new acting Number One to count on, as Ensign Tilly (Mary Wiseman) suggests engaging with the tyrant via the ruse of a Starfleet officer gone rogue on Book’s ship.

And that is where Keyla Detmer (Emily Coutts) comes in. The unexpected prominence of Detmer’s fight with post-traumatic stress disorder from her years of piloting starships in and out of dangerous conditions continues to be one of the best surprises of the year in Trek. From the very start of the series, Coutts has instilled Detmer with an appealing pathos that has helped ground many of the huge action sequences happening around her.

Beginning with the cranial injuries she first sustained on the USS Shenzhou and her long, piercing stare down of Burnham in “Context Is for Kings” — a moment that certainly indicated early signs of mental trauma — the helm officer has dutifully piloted the ship through asteroid fields, alternate universes and a dramatic landing on an icy terrain.

Her arc throughout this season has been nuanced and complex, filled with realistic highs and lows accompanied by no easy answers. Her epic dinner table meltdown in “Forget Me Not” that led her to seek help from Dr. Culber now stands in excellent contrast to her heroic “rogue mission” with Ryn and Grudge on Book’s ship.

In helping the crew best Osyraa, Detmer vitally takes agency over her internal struggles by going “full manual” and doing what she does best, all while helping Ryn confront his own demons by telling him, “If you face something, you can beat it.” It’s a bit of advice that she is finally beginning to understand herself in this difficult move to the 32nd century.

Making his second appearance of the season, Ryn (Noah Averbach-Katz) an empathetic Andorian who has suffered his own trauma and is extremely loyal to Book, is an interesting addition to the cast as a potential recurring character, especially when he reveals at the end of the episode his secret about the Emerald Chain.

Apparently, Osyraa and her crew are running out of dilithium, and that is why she was so hell-bent on getting Ryn back under her control. Averbuch-Katz is excellent as Ryn; he expertly balances his Andorian aggression and snark, with the ability to read the room and trust the environments around him. Hopefully, we will see more of him in future episodes!

As for Osyraa… well, honestly, we’ve definitely seen some better Trek villains. Time will tell on how her story will play out, but for now her scenery-chewing proclamations have been less campy and fun, and more overwrought and unfulfilling. This is especially true when she departs Kwejian with the near-comical decree: “You have just sealed your own fate and the fate of the Federation. I promise you will feel the full weight of the Chain.”

That cliché-ridden salutation came on the heels of a few other overstrung edicts, including this ode to Orion: “My ancestors knew that power is virtue, and there is no nobility in suffering. You do what it takes to get what you need, or you don’t.”

Pontificating from Osyraa aside, it was great to see Detmer and Ryn take out the Orion’s weapons (as she carpet-bombed the planet) via her piloting skills and Ryn’s inside knowledge of having served time working in the Chain’s scrapyards.

Elsewhere, Adira Tal (Blu del Barrio) is also trying to figure things out, both personally and in specific reference to unearthing a secret about the Burn. The wunderkind with the Trill symbiont has revealed to Paul Stamets (Anthony Rapp) that they prefer to be identified as “they” or “them” moving forward, as they’ve never felt like a she or a her.

The long-awaited revelation comes with the news that Gray is no longer talking to them anymore. They know he’s still there, but it feels like he is hiding. Adira and Stamets share a musical interlude  — one step closer to hearing Rapp sing on this show! — as the young genius confesses they wake up every day, never knowing which of their hosts they are going to feel more.

The confession, which includes Adira coming out to Stamets about their gender identity, as they admit he is the first person they’ve told outside Gray, feels like an important real-world parallel that the Star Trek franchise has done so well for 54 years. It’s a message to anyone waking up every morning confused, that there are avenues to pursue for help and all those different feelings and personalities have a place in defining who we are.

In the end, Adira impresses the crew with their stellar work on decoding a Federation distress signal that is coming from the center of the Verubin Nebula, where the Discovery crew thinks the Burn originated. The signal was first identified after some fancy technobabble deciphered it from that piece of music that has been reappearing for much of the season; we don’t know the answer yet, but expect Adira’s work to pay dividends very soon.

While so many of the crew were working on establishing their place in this new century, Georgiou (Michelle Yeoh) was focused on trying to not lose hers. In response to the blackouts that have been affecting her since meeting with Kovich in “Die Trying,” she finds herself in sickbay getting a deep analysis from Dr. Culber (Wilson Cruz) and Dr. Pollard (Raven Dauda).

“The Oracle of the Mess Hall,” as Georgiou hilariously refers to him is concerned that they can’t tell if her blackouts are physiological, psychological, temporal or interdimensional. The two go tit for tat in a number of different scenes, and we see another glimpse of the Mirror Universe flashbacks that have been haunting the former emperor recently, flashing images of a fallen friend (?) named San.

After sneaking out of sickbay with the test results, Georgiou learns that she is dying, although Culber confronts her again and says, “It’s not that cut and dry.” That storyline ends abruptly on that note, so we are left to add it to the many loose threads set-up by this unique episode.

What’s the real story with Georgiou? What is Adira’s algorithm going to reveal about the distress signal they are tracking? And why has Gray stopped speaking to them? Is Book really going to commit himself fully to Starfleet? And seriously, what catchphrase is Saru going to settle on as captain? A lot of questions were left very open-ended at the end of “The Sanctuary,” so we’ll have to wait for the next episode to start piecing some of it together.

OTHER OBSERVATIONS

• The episode features a quick return to the scrapyards on Hunhau, where we see a vengeful Osyraa playing with an ancient Star Trek: Picard-era combadge while feeding her nephew Tolor (Ian Lake) to a trance worm.
   
• Noah Averbach-Katz, who plays Ryn the Andorian, is married to Mary Wiseman (Tilly), and the two got to share a scene together in the mess hall in which he unveils his big secret.
   
• Osyraa’s ship is named the Viridian, which is a blue-green pigment that leans a little more green than blue. Naturally!
   
• Osyraa was portrayed by Janet Kidder — niece of actress Margot Kidder of Superman movie fame — who has appeared in several genre series and movies, including Earth: Final Conflict, Supernatural, Fringe and Arrow.

• The episode was written by Kenneth Lin and Brandon Schultz. For Lin, it is his first Star Trek writing credit, and for Schultz it is his third, having previously been credited on “Perpetual Infinity” and “The Girl Who Made the Stars.”
   
• This week marks Jonathan Frakes’ fifth turn in the Discovery director’s chair, and his 23rd overall with the franchise.
   
• Saru’s quest for a captain’s catchphrase is a great callback to Captain Freeman in Star Trek: Lower Decks — and quite coincidentally too, as this season of Discovery was originally planned to air before the series debuted.

When all is said and done, is “The Sanctuary” an all-time great episode of Star Trek: Discovery? Well, no. But it is a powerful episode, filled with connective moments that focus on some key character motivations, and will likely serve as an important link through the second half of the show’s Season 3 narrative.

How are you feeling about Detmer’s progress? Do you think Book is going to go full Starfleet? And are we ever going to find out the story behind his assumed named of Cleveland Booker?

Let us know in the comments below what you think about these questions, and the other story threads left open here, as Discovery rounds the corner into the back half of a very strong season.

Star Trek: Discovery returns Thursday, December 10 with “Terra Firma, Part 1” on CBS All Access and CTV Sci-Fi Channel. International viewers get the episode December 11 on Netflix, in all other global regions.