the story: The Borg return, and Data gains emotions.
similar to: "The Search" (Deep Space Nine), "Darkling" (Voyager)
my thoughts: After the monumental "Best of Both Worlds" that served as the blockbuster introduction (for many, although they debuted in "Q Who?") to the Borg, and the much more contemplative follow-up "I, Borg," how the Collective showed up again was a crucial and probably doomed to be controversial affair, especially when later appearances (Star Trek: First Contact, Voyager) seemed to contradict the conclusions to be found in "Descent."
(For those who want explanation, it could be argued that the Borg who appear here are the remnant of the invasion force from "Best of Both Worlds," where the rest of the Collective remains as it always was in the Delta Quadrant. Remember that the Borg were already at the fringes of Federation space as early as the end of the first season, probably a scout force that may or may not be related to the cube from "Best of Both Worlds.")
Putting aside Borg developments, the key component of this half of the story (it concludes in the seventh season premiere) is Data's struggles with emotions, how they become addictive and uncontrollable (in ways completely different, and darker, than depicted in Star Trek Generations). Simply put, this is Data like you've never seen him before, and it makes for riveting drama.
Voyager's Doctor experiences a whole different artificial existence. He would often manipulate his own programming, with wide-ranging results, some of them as nasty as what Data experiences here (see: "Darkling"). Data usually experienced that sort of thing due to the manipulation of his android brother, Lore, who is of course once again responsible (the plot thickens in the second part on that score).
"Descent" is foreshadowing for the kind of storytelling Deep Space Nine would tell on a regular basis, starting with the full reveal of the Dominion in the two-part "The Search," which opened its third season. Aside from the Klingon saga (last touched on in "Rightful Heir" a few episodes ago), Next Generation was still a relatively episodic adventure, where big events were mostly self-contained. Although the following seventh and final season continued this trend, it's easy to imagine that if the series had continued, it might have eventually embraced further serialization, and "Descent" is an example of what that might have looked like. Lore had been around since the first season. This is the story where his saga concludes, in impressive grandiose fashion. But again, more on that next episode.
The first part of "Descent," meanwhile, is fascinating in its own right. Like "Birthright" before it, the episode is an ambitious attempt to tell two separate, and yet related, stories. This half is all about Data's initial journey, and it can't help but feel more vital than its follow-up, as we're in the familiar context of his fellow officers the whole time.
For the boldness of its vision, it's another of the unusual classics, but a classic all the same.
criteria analysis: franchise - series - character - essential (all criteria met)
Brent Spiner (Lore)
Natalia Nogulich (Nechayev)