While en route to a top-secret diplomatic mission to meet representatives of two Klingon houses, Sarek (James Frain) is injured and his transport ship disabled by a suicide-bomber who identifies himself as a member of a group of logic extremists who oppose Vulcan-human integration and Federation involvement. Sarek’s distress is sensed (and felt) by Michael Burnham (Sonequa Martin-Green), who persuades Captain Lorca (Jason Isaacs) to mount yet another Discovery rescue mission.

In the meantime, Lt. Ash Tyler (Shazad Latif) is proving his loyalty to Captain Lorca and is promoted to security chief aboard Discovery. Lorca assigns him to pilot Burnham’s shuttle through the Yridia Nebula in an attempt to rescue Sarek. With help from Cadet Tilly (Mary Wiseman), Burnham is able to connect with the unconscious Sarek by way of a super-juiced-up mind-meld augment that taps into Sarek and Burnham’s shared katra.

The successful link exposes Burnham to a painful Sarek memory and a dark secret he’s protected: Burnham was never denied admission to the Vulcan Expeditionary Group years earlier, as she was lead to believe; Sarek was required to make a choice between his two non-fully-Vulcan children, Burnham and Spock, and he chose Spock – a decision he never reveal to Burnham.

Sarek is successfully rescued but his injuries prevent him from resuming his mission with the Klingons on Cancri IV. Standing in for him is Admiral Cornwell (Jayne Brook), who, despite her close romantic ties to Lorca, is intent on removing him from command over concerns for his mental stability. The peace talks end up being a Klingon trap, Cornwell is captured, and the episode ends with Lorca leaving the decision to rescue her in the lap of Starfleet.

This episode is a fine vehicle for Lorca, and Jason Isaacs continues to add layers to a complicated character. The knee-jerk reaction in a review like this is to focus on the Sarek-Burnham plot and that surprise character revelation, but let’s begin with Lorca here. He goes from stern mentor in his early scenes with Tyler, to compassionate and accommodating captain with Burnham, to charming manipulator with Cornwell, and then to paranoid war soldier with a phaser at the ready by episode’s end.

As fans, we’re we’ve grown accustomed over several series to seeing our captains struggle with the aftermath of war or being victims of alien imprisonment. Discovery brings a raw intensity to that familiar captain’s struggle.

When a startled Lorca leaps out of bed and aims his phaser at Cornwell, it becomes especially clear that Lorca is not a well man. But he’s a guy that doesn’t want to lose his command, and he’s not willing to step down, even though it may be in the best interests of Starfleet. His decision to essentially abandon Cornwell to the Klingons (or, as he put it to Saru, leave the decision to Starfleet) may not be the most admirable thing for a Star Trek captain to do, but it makes sense as something his character would do. Cornwell has now become a threat to him and his career in Starfleet.

The beauty of Star Trek: Discovery so far is how it has managed to tell personal stories against a very dark backdrop — in this case, war. I’m reminded of what made “Yesterday’s Enterprise” from The Next Generation such a standout installment, and that was a very personal, and redemptive, story about Tasha Yar. That episode also featured the Federation at war with the Klingons, but it all took place in an alternate timeline formed by a temporal rift.

As intriguing as the war timeline was, it was never the real story in “Yesterday’s Enterprise.” It was all about Tasha and her finding a renewed purpose (and, some could argue, a corrected fate) aboard the Enterprise-C as it attempted to restore the proper timeline.

“Lethe,” in the best Star Trek traditions, doesn’t get lost in the muck and dirt of this overarching war story. It’s all about character. We see the friendship and mentorship between Tilly and Burnham continue to grow in a light-hearted scene early in the episode, when the two are exercising. We also, of course, get some significant character development when Burnham discovers Sarek’s secret and confronts him about his decision on that fateful day on Vulcan.

Sure, the mind-rescue plot feels a little too familiar for Star Trek and I’m still not sure I’m on board with the series’ decision to shoehorn Burnham into Sarak’s family tree; there’s something a bit too obvious in terms of fan service and legitimizing Burnham into Star Trek canon. Could they not have created another Vulcan character for this part?

That said, Sonequa Martin-Green and James Frain file fine performances in this episode. Burnham’s expression upon learning she has been denied acceptance is heartbreaking. Burnham’s story is capped by a wonderfully realized scene in the end where Burnham bonds with Lt. Tyler concerning her emotional struggles with Sarek.

That scene with Tyler, however, did raise a question in me. As satisfying as it was, I wondered initially why she chose Tyler with whom to have this personal talk – as opposed to, say, Tilly. Is it because Tyler, like her, is an outsider who was selected and favored by Lorca? Is it because she’s romantically interested in him? Or is it because we need to be clued-in that Tyler will be playing a larger role in future episodes, especially as it relates to his relationship with Burnham?

On the downside, Stamets’ “groovy” scene was a bit too weird for comfort. The show needs to quickly resolve what’s going on with him after his assimilation into the spore drive. I kept getting uncomfortable flashbacks to “drunk”-Data from TNG’s “The Naked Now” or from the Star Trek Generations movie, where Data turns giddy after assimilating his emotion chip.

And what’s with the food slot on Discovery? I’m not sure it’s a downside, but it’s certainly amusing to hear a replicator respond to a request – in this case, from Burnham – that the order is “appetizing and nutrient-filled”.

It’s worth noting that the “Lethe” teleplay is credited to Joe Menosky, who filed some of Star Trek’s finest episodes during the show’s Rick Berman era, including “Darmok” – a fan favorite that’s often regarded as a high-water mark for The Next Generation.

It’s difficult to see where Menosky’s fingerprints are on this episode, but what we do have is an installment that nicely strikes a balance between its light and dark elements, as some of the better crafted Star Trek stories have always done.

Star Trek: Discovery returns this Sunday with “Magic to Make the Sanest Man Go Mad.” Watch for our ongoing Canon Connections series to continue later this week as we look for the ties to Trek‘s past in this most recent episode!

Rob Heyman is a freelance journalist and entertainment critic. He is a regular contributor to both TrekCore and The Logbook, where he has written episode reviews of Star Trek: The Next Generation, Voyager, and the Star Trek movies.

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