
The Enterprise is investigating the disappearance of another Federation starship through an area of space that can only be traveled through via a "corridor" between large concentrations of radiation.
They come across a disabled Ferengi ship that soon attacks the Enterprisem believing them to be the cause of their disablement. Picard's able to convince them they're not and able to get some more information on the possible whereabouts of the lost starship in exchange for helping the Ferengi ship to get underway again.
They investigate the new set of coordinates and only find debris but are unable to determine if it belongs to the missing ship before they're attacked by a nearby probe they communicate with (believing it to be a "flight recorder" from the lost ship.) The probe's attack disables the Enterprise the same way the Ferengi ship was disabled. The Enterprise is then boarded by two alien scientists.
The scientists are residents of a nearby planet and the believe the heavy concentration of warp-fields using that specific region of space is having an "environmental" impact on the area. In essence, it's wearing out the barrier between normal space and subspace (the "dimension" in which ships travel to achieve super-luminary speeds) and it's having an impact on the habitability of their homeworld. They feel that if nothing is done soon the "corridor" will rupture spilling subspace into normal space which would not only make the area impassable but would have larger environmental impacts on their home planet.
A few years prior they had petitioned Starfleet to investigate this but Starfleet didn't find there to be enough evidence from the early research and the aliens have been unable to get Starfleet to listen to or accept their new findings.
Picard promises they'll look at their research now, providing they help the Enterprise get underway again in order to find the missing ship. The aliens agree to the terms and also promise to disable the other "mines" they have in the corridor.
Looking over the research Geordi and Data find there's some merit to the research but still not really enough to go on but they and Picard promise to send it to Starfleet and with Picard's suggestion Starfleet will send out ships to conduct more extensive research. More immediately they're concerned about the missing ship.
The alien female sees this as just further delay tactics from Starfleet/The Federation and takes her ship into the corridor and causes a warp-core breach on her ship, the breach is enough to cause a small subspace tear in the area, proving the aliens' theory.
The tear is impassable and stands between the Enterprise and the missing ship, while the Enterprise is far enough outside of the tear to not be impacted by the shockwaves it's causing the missing ship is inside the tear and cannot last much longer. The Enterprise cannot use warp-drive to get through the tear and impulse is too slow to be of use. Luckily, Geordi and Data find a way for the ship to "warp coast" through the tear without their warp-drive being a problem. While coasting through the tear the other ship attempts to leave using its warp-drive which causes the tear to grow and damages the ship more. Data is able to work out a way for them to scoop up the ship's crew and for them to extend their "warp coast" enough to get out of the tear.
Now with solid, un-ignorable, evidence Starfleet's forced to investigate the impact warp-drive has on subspace as well has cease use of this corridor in space. They also impose a "warp-speed limit" on starships outside of emergencies.
A year or so later they find that if they make the nacelles move slightly before entering warp they can avoid this damage to subspace or, I dunno, it's generally fixed and never worried about again.
-----
Sigh. The Enterprise deals with ecoterrorists.
Honestly, I don't find this episode to be too bad but the "message" in it is sort of weak and, honestly, kind of confusing. I guess I understand and can even accept how this "tear" occurs in this area of space (since it's heavily used over a very specific area) but not sure how this expands to systems-wide "speed limits" through areas of space that aren't being abused by subspace overuse.
Eh, it doesn't matter, I guess, since a solution was worked out and was never a problem again.
We could question the female terrorist's motivations and her end-goal since creating the tear would have a dramatic impact on her planet but terrorists are rarely rational and sometimes see taking extreme measures as being the only way to force change.
It seemed like here the episode *wanted* to say something and be something but it really didn't have enough to build an entire episode around it so we're given something of a "B-Story" AND a "C-Story."
The B-Story being about Geordi thinking of getting a cat as a pet and tries it out with Data's Spot (who's a female now when it was a male a couple episodes ago) and confronts Data on Spot's lack of training and discipline.
The C-Story being about Geordi having a friendly competition with a colleague on another starship over engine status.
Oh! And there's a D-Story about some sensors or something acting up giving us a thrilling several minutes of Data and Geordi crawling through jefferies tubes trying to fix them.
There's a lot of padding in the episode is what I am saying. Hell, even the bullshit with the Ferengi is sort of thrown in there and only scantly connected to the main plot.
The episode also gives us probably one of the "worst" "cold opens" for TNG, a trend that'd become more commonplace on VOY and would be horribly bad during ENT. This being a different from most opening-teasers where the story is established in some manner, and we just get a nonsense scene just to sort of having something happen before the opening credits sequence. In this case, Geordi looking for Spot around his quarters before they called to the bridge for their mission.
Padded, padded episode. It's not terrible, not good either.