The Enterprise becomes ensnared in a field that pulls the ship along like a boat in a current. It turns out the current is actually a swarm of two-dimensional life forms that exist in space on a flat plane (which, of course, is not unlike how space travel is often depicted in Trek anyway). The crew must figure out how to escape the current without hurting the 2D-beings. The sci-fi gobbledygook surrounding this storyline is not one of TNG's best examples of sci-fi gobbledygook.
Coinciding with this encounter, Counselor Troi's telepathic abilities suddenly vanish. Is there a connection? Gee, what do you think? Will Troi have her abilities back before the hour is up? I wonder. "The Loss" is a better title than "Two-Dimensional Life Forms" and it describes the more relatable of the story's equal-time-shared plot. I had sympathy for Troi's loss of her ability to sense other people's feelings, whom she aptly now describes as "surfaces without depth" and "projections." But the depiction of this just doesn't work. Troi has a meltdown where she snaps on Beverly, and I didn't buy it. And her almost immediately resigning her post borders on silly as knee-jerk overreactions go. Dramatically, the net effect of a helpless Troi feels more shrill than effective. Aren't TNG characters supposed to be more perfect than this?
The 2D-beings plot turns to tedium and forced jeopardy simultaneously. We've got the 2D-beings headed toward a cosmic-string fragment (with the gravity of 1,000 black holes, if I heard right, although one would've been sufficient) and the only way for the Enterprise to escape comes when Troi hits on the idea of "moths to a flame." Of course, creating another "flame" in this instance involves reams of cascading technobabble that … oh, never mind.