That ominous rumbling in the distance is some of Star Trek: Discovery’s bad habits rolling back into town.

*SPOILER*

Despite the Admiralty-mandated joining of forces, there’s a distinct lack of urgency to the search for Spock in this episode. Instead, we’re treated to the origin story of Saru as the first Kaminarian superhero; their Daredevil: the Kelpian without fear. Brace yourself for “The Sound Of Thunder”.

With Saru pondering what the loss of his threat ganglia means for him and his people and trying his hand at being a life-coach to the newly resurrected Culber, it’s up to the rest of the crew to continue the investigation of the ‘red angel’. While Pike and Burnham contemplate the idea the entity is a time traveller, Tyler raises the disturbing possibility that its intentions are hostile rather than benign. But there’s little time to ponder hypotheticals as another red burst occurs: this time in orbit around Kaminar – Saru’s home planet!

It was pretty clear from the Short Trek “The Brightest Star” that we would, at some point, be going back to Saru’s homeworld this season but I’ll admit the rapidity of the return has given me a little bit of storyline whiplash. There’s a feeling that, having successfully kept all the multiple narrative plates spinning merrily over the past few episodes, wobbles are starting to creep in and sooner or later, something’s going to crash to the floor.

In the meantime, we finally get a lot more information on the Kelpian society and learn more about their oppressors in The Great Balance, the Ba’ul. It’s never really made clear why Starfleet was content to turn a blind eye to the treatment of the Kelpians and although the Prime Directive is mentioned in passing, it’s plain that neither Pike or any of his command crew are remotely concerned about bending the rules when it suits them.

There’s a wonderful moment when Saru’s new in-your-face attitude gets him into trouble, made doubly funny given he’s grievously insulted by Pike’s implication that he may disobey orders while on the away mission, suggesting his memory of his previous away mission seems to have disappeared with his threat ganglia. Ultimately he does get to go down to the planet and kind of ends up doing exactly what Pike said he would do but his visit is cut short by the appearance of the Ba’ul.

“The Sound Of Thunder” definitely kicks up a gear when the Ba’ul make their presence felt. There’s a lot of posturing between them and Pike regarding the willingness to use force and it’s sort of implied that the Ba’ul are technologically superior to Starfleet but then again, Pike doesn’t seem overly concerned about the threat they pose to his ship and the lives of his crew so maybe our ‘good’ captain has something of a death wish? Starfleet sure can pick ‘em where Discovery’s C.O.s are concerned.

The Ba’ul want Saru back and will stop at nothing, including harming the rest of the Kelpian population and when Pike refuses to hand him over, Saru becomes increasingly belligerent and disobedient until he’s ordered off the bridge, sashaying his way to the transporter room in a manner which would make RuPaul proud. Burnham quickly twigs to what he intends to do and runs to catch up with him but obviously doesn’t stop him. The stage is then set for super-Saru to bring down the Ba’ul and free his people, which he does in the most astonishingly un-Trek way possible.

There’s plenty of mention of the sphere database in this episode, something that’s well on its way to becoming yet another of Discovery’s MacGuffins alongside the spore drive and Starfleet’s apparent willingness to look the other way as its most sacred tenets are trampled over by any of Discovery’s officers. In fact, it’s the sphere’s records that provide the crew with most of their information on the Ba’ul and Kaminarian history, as well as the means to implement Saru’s desired solution. James T Kirk may have gained himself a reputation as an inveterate rule breaker and even Picard, Sisko and Janeway played fast and loose with the Prime Directive on more than one occasion but I doubt that any of them, in their wildest moments, ever contemplated pushing an entire species through hyper-accelerated super-puberty. Horrified by the idea of an entire planet of moody, hormonal Kelpians, the Ba’ul decide to enact some kind of etch-a-sketch protocol and wipe the planet clean only to be stopped by the red angel itself who manifests at the Ba’ul’s Fortress Of Doom^TM and shuts down their power. It’s a big relief for Saru and his shipmates who, without the red angel’s intervention, would have been directly responsible for provoking the genocidal extinction of the Kelpians.

“The Sound Of Thunder” is a busy, action packed episode which manages to remain entertaining and spectacular enough to cover up the fact that it’s one of the most un-Trek-like episodes yet, despite its obvious legacy Trek influences. The situation between the Ba’ul and the Kelpians evokes the “Star Trek: The Next Generation” season one episode “Symbiosis” which ended with Picard performing a similarly cruel-to-be-kind act of enforcing an entire planet to go cold turkey to cure their addiction. The production team obviously didn’t stop there and continued on to watch the next TNG episode as the appearance of the single Ba’ul we get to see owes a great deal to notorious Tash Yar terminator Armus from “Skin Of Evil”. Even the curious manipulations and motivations of the red angel feel like a nod to, if not the adventures of Captain Archer then certainly Scott Bakula’s previous role in Quantum Leap. Could the red angel just be “Star Trek: Discovery”’s version of Al and Ziggy?

A lot happens in “The Sound Of Thunder” and yet it feels like we don’t move forward all that much. The series arc ends up more a plot device than progression and, unless it’s explored more fully next week, the radical societal change on Kaminar feels rushed and incomplete. We get some fascinating titbits about Culber’s resurrection but their implications too are left hanging – hopefully, to be picked up again later but the way the series is apparently tying up plotlines feels like its clearing the decks and I hope they’ve got enough of substance to make all this rushing worthwhile.