After the last fortnight's diversion to write out Georgiou, we get back to the main arc plot with the first part of a serialised story that will head out the season. Decoding the data from the Verubin Nebula, Discovery heads to find the Kelpein ship and its one remaining survivor: the eponymous Su'Kal, who was only a child when the ship crashed into a planet in the middle of the nebula. However, things are hotting up with the Emerald Chain: Osyraa has been posturing near Kaminar (pretty much confirmed as still a Federation member) in an attempt to draw Saru out so she can capture Discovery for its spore drive. She's not wrong thinking that it will get Saru worried, but hasn't reckoned on another Kelpien crisis to drag him to the other side of space. In a classic series move, an away team with all the most vital members of the command crew go to the crashed ship: Saru, because Kelpiens; Burnham, to keep an eye on Saru; and Culber, for his medical expertise (the place is riddled with radiation). Saru leaves Tilly in charge as Acting Captain, and she's pretty awesome, even when Osyraa turns up and attacks.
It's a strong, inventive episode, even though the actual plot is very straightforward. It's full of fascinating visuals and cutting dialogue, and the major characters pretty much all get a moment of focus (although the Adira/Gray plotline, while reopened, is still on the backburner). One thing I neglected to mention last week was how well Book has integrated as an unofficial member of the Discovery crew, and he continues to work well this week as a problem solver/local knowledge guy/handy space pilot. The main focus, though, is naturally on Burnham, Tilly, Saru and Culber, the latter of whom is particularly impressive. Since returning to the world of the living, Culber has slowly come to terms with his new existence, and is the only member of the original crew for whom arriving in the future has been nothing but positive. In the 32nd century he has found a purpose, and isn't afraid of risking his life if it means he may save another. Wilson Cruz puts in a beautiful performance.
Beaming to the ship, the away team find themselves in a truly spectacular holographic environment. It's like a gothic fantasy realm, a very different sort of location than most in Star Trek (you get a bit of that in Klingon stories sometimes, otherwise it's very rare). More interestingly, the programme changes the appearance of the away team so that they don't spook Su'Kal. This doesn't really make any sense, but it's a fun touch making Burnham a Trill and Culber Bajoran, but the big change is Saru. For the first time in the series, Doug Jones gets to play his character without make-up, and it really hammers home just how brilliant an actor he is. He's at once almost unrecognisable and absolutely Saru. You have to wonder just how compromised (shades of Spock in Star Trek 2009 there) Saru is becoming due to the involvement of the Kelpiens, and whether he'll actually be rejoining the ship when this is over.
Burnham doesn't really get anything new in the way of character development, but there are some very nice moments with Saru, and her role pretending to be a hologram for Su'Kal is a strong scene. Perhaps the most impressive actor in the episode, though, is Bill Irwin as Su'Kal himself. He gives an astonishingly good performance as a character who is not only an alien, but who has been alone since childhood and is unused to the company of anyone who isn't a hologram. It's an endearing and fascinating performance, and that's before the sudden revelation that he caused the Burn.
Su'Kal's unexpected ability - seemingly due to his body adapting to a radiation-soaked environment on a planet made from dilithium - means he can emit a huge wave of energy that destabilises dilithium. It really puts me in mind of X-Men, with someone who has an innate ability that could endanger the world (or galaxy, in this case). Indeed, I wonder if the hyopthesis that Su'Kal has adapted due to his environment is wrong, and that he's a mutant, and was stranded in the nebula deliberately. But maybe that's a stretch. There's a strange but intriguing side plot involving a kelp monster that represents Su'Kal's fears, which surely has to lead up to something bigger.
Meanwhile, Discovery is attacked by Osyraa, and Tilly is brilliant as Acting Captain. Mary Wiseman gives a great performance as someone absolutely bricking it but still determined to command the ship. Osyraa is better this time round as well, with Janet Kidder appearing much more imposing and threatening this time round. Her psychological tactics work well with Tilly, although she doesn't break through, but her experience means she's clearly going to get the better of the ensign (at least in the short term). This is what happens when all your command crew bugger off on an away mission. Tilly's initial plan to jump away and come back for the team is, of course, absolutely the right thing to do, even as Stamets protests. In the end, though, the Chain come for the ship and we end on a great cliffhanger.
The original title for this episode was "The Citadel."
We see some footage of the admission of the Kelpien and Ba'ul Alliance into the Federation. It seems that not only is Kaminar still a Federation member in 3189 - and being threatened by the Emerald Chain - but that the two intelligent races of the planet made peace and unified prior to joining.
The planet Su'Kal is stranded on is named Theta Zeta and is classified as class-Y, an especially hostile class that was introduced on Star Trek: Voyager.
The Kelpien starship is named the KSF Khi'eth 971014. I'm guessing KSF stands for Kelpien Space Force or similar. I don't know who Keith is.
Kelpiens show red spots on their temples when pregnant. There's a hologram of a Kelpien elder on the ship, which Saru says appears far older than any Kelpien he's ever seen. We don't know how long Kelpiens live, and Saru probably doesn't either, given the culling, but Su'Kal's been alone for about 120 years. That said, it's possible he actually looks older than he appears here, and it's more holographic trickery.
Discovery can cloak now, which might have been worth mentioning. Gratifyingly, though, there are still limits to cloaking devices, and the ship can't jump while cloaked. Given the lack of zap-zap action, ships probably can't fire while cloaked either.
There's a network of transwarp conduits that the couriers use - which allows Osyraa to get to Verubin quickly - but they're incredibly dangerous and Book thinks she's nuts for using one. Presumably they need to be maintained in some way to keep them safe for travel and the dilithium shortage has led to their being neglected.
There are some fun aliens in the holo-flashback of Kaminar's induction into the Federation, including a guy with a halo of tentacles on his head. They wear yet another new Starfleet uniform but we still don't know when this happened.