SPOILERS follow for Star Trek: Discovery's "Lethe"
The sixth episode of Star Trek: Discovery, "Lethe," is a satisfying character piece that doesn't quite match the series high so far, "Choose Your Pain," but provides important backstory for Michael Burnham and her foster father Sarek, while also giving us a better glimpse into the motivations of Captain Lorca. All this, and "DISCO" t-shirts for the crew!
Lured into a trap by a renegade Vulcan (a "logic extremist"(!)), Sarek lies near death in a small, crippled shuttle lost in a dense nebula. His telepathic death agonies reach Michael Burnham, who asks a strangely sympathetic Captain Lorca for permission to mount a rescue mission. Burnham, Ash Tyler, and Sylvia Tilly board a shuttle, homing in on Sarek's katra in an effort to locate and rescue the dying Vulcan.
Meanwhile, Captain Lorca's commanding officer, psychologist, and lover Admiral Katrina Cornwell - surely not the greatest combination from a human resources perspective - pops aboard Discovery for a visit.
Harkening back to the old a-plot/b-plot structure of 90s-era Trek (perhaps unsurprising, since this episode was written by TNG veteran Joe Menosky), "Lethe" juggles two stories about relationships and past trauma to good effect. We learn more about the Sarek/Michael relationship, and we're introduced to young Amanda, played here by Canadian actress Mia Kirshner. It turns out that Michael and Spock were both in the running for a prestigious assignment to a Vulcan expeditionary force of some kind, only for an officious Vulcan to tell Sarek that there was no way two non-Vulcans (in their eyes, the half-human Spock fell into that category) were going to join that elite club. Michael learns that Sarek reluctantly chose Spock, and then lied to her, saying that her application had been rejected all those years ago.
Not only is this an interesting turn for Michael's relationship with Sarek, it puts the decades-long story about Spock's relationship with Sarek into a fascinating new context; as it turns out, Sarek should have chosen Michael, since Spock wound up rejecting his father's wishes by joining Starfleet. Sarek's choice was a waste. No wonder there were some hard feelings--even for the supposedly non-emotional Vulcans.
Naturally Sarek is rescued in the end, but not before Michael has a lot of new feelings to process.
Aboard Discovery, we find that Lorca is clearly traumatized by losing the crew of his former ship, the USS Buran, and that his friend and commanding officer is clearly concerned that Starfleet put him in command of a new ship too soon. In fact, when Lorca awakens from a post-coital sleep with Admiral Cornwell, he suffers an episode of PTSD and pulls a phaser on her before realizing what he's doing. Cornwell puts Lorca on notice, saying she's going to remove him from command.
Before she can make good on her threat, however, she winds up having to take over the mission that Sarek was initially supposed to handle. Naturally it's a trap, and she winds up a prisoner of the Klingons. When Saru informs Captain Lorca, Lorca shrugs and says he wishes he could help, but the Admiral herself ordered Lorca to stop being so reckless and get authorization from the admiralty before undertaking any out-of-scope missions.
A simple plot summary doesn't really capture all there was to like here. Aside from the fascinating new context for an old piece of Trek lore, we're treated to an evolving exploration of Lorca's nature - is he evil? Or just traumatized? Is he sincere in that he's trying to be a better captain by following orders, or is he just using that as an excuse, hoping that the Klingons will kill Cornwell before she can relieve him of command?
And what's up with Stamets, who seems completely tripped out in his brief scene this episode? Is he merely suffering the effects of being the new biological navigation computer for the spore drive, or is he some kind of evil mirror duplicate, as hinted at in the creepy closing shot of last week's episode?
Also: loved the callback to the food slots from the original series, Cadet Tilly continues to delight, love the DISCO t-shirts, and the name-drop of the Constitution-class Enterprise. She's out there somewhere, ten years before Kirk took command! So cool.