Nutshell: Not awful, but horribly uncompelling.
"Displaced," unfortunately, exemplifies the heart of what much of Voyager as a series has become: A plot-based show that tells nothing about the lone starship's true difficulties or identity, but rather a relatively brain-dead series of events that has no lasting effect or consequences.
Last week's "Distant Origin" may have been a little outlandish and silly at times, but at least it had some ideas and dialog that ultimately added up to mean something. "Displaced" doesn't add up to mean much of anything. It's simply mediocre to the extreme. The plotting isn't terribly bad, but it really doesn't hold anything of interest, either. There isn't a single relevant argument or insight to be found in the episode. Instead, the entire show is merely an "action-packed" example of Our Heroes versus the Bad Guys.
That isn't by any means bad by definition. I can enjoy superficial adventure as much of the next person. Unfortunately, the big problem is that even the action in "Displaced" lacks a sense of cleverness. It's just kind of there.
In "Displaced," the Voyager crew slowly begins disappearing, one by one, being mysteriously teleported away and replaced by a race of confused people called the Nyrians. Before long, it becomes clear that the Nyrians are not the innocent-seeming party in the affair that they claim to be. As the numbers in the Voyager crew begin to dwindle, the Nyrians suddenly attempt to hijack the ship, leading to the routine phaser battles and crawling through the Jeffries tubes. Chakotay, one of the last to be taken, attempts to make a last stand by sabotaging the ship's systems, but he's completely outnumbered, and surrenders the cause after downloading the Doctor into the holographic emitter, unbeknownst to the Nyrians. (Why Chakotay doesn't arm the ship's auto-destruct sequence is beyond me, but I guess if the ship was blown up there wouldn't be a series, now would there? Then again, based on past episodes, the concept of the auto-destruct system on Voyager is so flawed that it defies usefulness: Not only can it be armed by one person, but it can be disabled by an external attack, a la "Basics, Part I.")
The entire crew, once transported off Voyager, finds itself in an Earth-like environment, where the Nyrians explain to them that they kidnap crews and steal ships rather than waging war. It's much "less costly" and "more humane"—the opposing sides are simply imprisoned in specially designed biospheres within the Nyrians' ship.
I don't want to go too far into the details of the crew's escape, because I'll just get too bored with synopsis. It involves (1) the crew's alliance with an alien from another biosphere who has learned how to access the "portals" that allow movement from one biosphere to another and also into the access areas of the Nyrians' vessel; (2) the rigging of Doc's "eyes" to find these invisible portals, which leads to a rather amusing line where he sarcastically remarks on his new career as a "tricorder"; (3) Janeway's and Tuvok's gaining access of the Nyrians' computer to acquire important technical information; (4) an extended chase scene in which Torres and Paris lure Nyrian pursuers through a frigid biosphere, which buys Janeway and Tuvok time to accomplish the feat of (5) gaining access to the Nyrians' teleportation device.
The execution of this plot consists of much conveniently acquired knowledge and average chase scenes.
Plot aside, there are some decent character bits in the episode. I particularly liked Doc's personality throughout—just his normal irascible self. Then there's the sparring between Tom and B'Elanna, which also works for the most part, especially at the very end of the show, which manages to say everything without resorting to excessive, all-telling dialog, but instead just a smile and some silence. There's also an amusing exchange early in the episode between B'Elanna and Harry regarding B'Elanna's "hostile" disposition.
Janeway is placed in the role of a no-nonsense heroine who constantly cops a confrontational attitude with the Nyrians—which could've and would've worked if it had been written with a little more charisma and a little less posturing. The ending, where Janeway gains control of the Nyrian teleporter and beams them into the frigid biosphere to force them to release the prisoners (Nyrians are vulnerable to the cold), could've been a delicious scene—but, like much of the episode, it's simply too nondescript.
We were supposed to be cheering the Voyager's success, I suppose. Personally, I felt kind of insulted at the smug, standard-issue premise of "Our Heroes save all the effete, imprisoned alien cultures by single-handedly beating the Bad Guys." Most of the crew's success, unfortunately, can be credited to the Nyrians' stupidity rather than the crew's cleverness—never a good sign in an action setting. For example, why in the world would the Nyrians leave the crucial areas of their ship unguarded? And why don't the Nyrians simply seal off the frigid biosphere that Tom and B'Elanna venture into, instead of following the two inside and freezing themselves? And after overpowering a Nyrian who has a fully-charged phaser, why don't Tom and B'Elanna pick up the phaser instead of simply walking away from it? And so on.
"Displaced" is an episode that demands passive viewing. Just turn off your brain; it will definitely be better that way. Still, even with brain shut off, I cannot recommend this episode. There's just not enough cleverness to the story, even as an action show. It prompts boredom and disinterest in too many stretches.