Another good, but not quite great episode. There was no real morality tale here, no sudden "twist" which made the cast have a deeper understanding of the Gorn. It's not even about the Gorn really, as they remain totally unseen, not only not existing as characters, but not even existing as props (other than the ships of course).
What the episode is ultimately about - as has been the case throughout the season to date - is character. Oh, there is a plot here - a well-executed mashup of submarine-style cat and mouse (ala Balance of Terror or Starship Down) and seeing the Enterprise in ruins with the various sections of the crew fighting to survive (ala Disaster or Damage). But the various crises really only help us to understand the main cast better.
This is clearly meant as a La'an episode, with it opening and closing with a personal log. The "A plot" as it were has a complete and coherent character arc for her, as she moves from attempting to ignore and suppress her childhood memories of the Gorn attack to coming to the understanding that she must use those memories (via mind meld assist) in order to complete the mission and help save everyone. I have to say that the examination of PTSD here is so much better executed than the attempts that Discovery made. I do think the little voice cameo of Michael Burnham was completely unneeded though, and downgraded things a bit for me. Plus the whole semaphore system of the Gorn made little sense (how could a child remember it that well from decades prior?) but I'm willing to accept it as dramatic shorthand. I did like how La'an wasn't magically fixed at the end of this episode - there's clearly more she isn't remembering.
La'an's journey however is just part of what happens here, as despite it being her character journey, it's more of an ensemble than any of the previous episodes. There's the mini-arc with Hemmer and Uhura, where she starts the episode having to prove her worth to him...which of course she ultimately does. There's the sick bay drama, which eventually leads to Una's surgery. There's the cat-and-mouse on the bridge, which gives Ortagas a chance to finally do something. We're only four episodes in, and I feel I have a good idea who everyone is on this show now, with the possible exception of Chapel.
I also need to say how refreshing it is to have a modern Trek show where everyone acts...like professionals. Too much of DIS and PIC (particularly in the season that just ended) involves grown adults with high-stakes jobs acting like adolescents in the middle of a major crisis, focusing on their own emotional turmoil rather than their freaking jobs. La'an is put through the wringer here, and aside from a few moments where she freezes, she keeps it under control. Pike is a rock-solid captain (his pep talk in the third act was genuinely inspiring). Finally, it's also refreshing that almost every member of the main cast (arguably not Una, since she was unconscious for much of the climax) had a valuable role to play in solving the crisis, meaning you cannot point to one action which comprehensively "saved the day." This was some pretty complex plotting, and I'm impressed, even if it's not the most original story imaginable.