Well, that was different.
Something about the vibe of this episode made it feel like a backdoor pilot to a new series. Perhaps it was the introduction of the el-Aurian officer, who was slotted into "main character" mode pretty neatly? Perhaps it was the extended introduction of a new setting, which felt a character of its own. Regardless, something about the episode felt "very special" after four episodes of filler.
There were a lot of callbacks here, from the doctor infected by the Tarchannian virus to the anaphasic lifeform infecting the beluga to the numerous TOS/ENT references with antiquated technology and uniforms. Yet I felt like this episode wasn't really relying on fan callbacks to tell the story, and was doing something new we hadn't seen in Trek before.
The A/B structure here was also relatively subtle - so subtle I didn't notice it while watching. The main thrust was clearly related to Mariner's arc accepting that though she was at her lowest when she served there, that didn't make Starbase 80 cursed itself. The "B plot" was the wild goose chase of Freeman and Ransom trying to find the chief engineer. Though this was mostly just filler, I did like the little touch Freeman had at the end, recognizing that the base was a bunch of scrappy underdogs, just like them.
One thing the episode wasn't, however, was funny. But I didn't think it was even particularly trying to be funny, unlike some of the earlier episodes this season, going for more of a spooky vibe.
On the whole, I think it's my favorite episode of the season yet, because it was trying to do something somewhat new/different in a season which has thus far been full of pretty stereotypical Lower Decks adventures. Hopefully, the season will close strong, as we only have five of these left.