There's nothing really glaring wrong with this episode - the B'Elanna/Tom stuff is even...OK...but it certainly won't knock your socks off, and there are some minor problems with the plot and visualization that I notice.
Memory Alpha has the details - it's a derivative plot with elements drawn from various prior Trek episodes and science fiction novels, but it's OK to watch.
First...a few of my favorite niggling plot problems from this episode just to amuse myself:
- They say that the Nyrians need a temperature of 45 degrees centigrade to feel comfortable. So...when we see Voyager crew members exposed to that temperature in the halls of the Nyrian vessel or in Sickbay or the cargo bays on Voyager...why aren't they POURING sweat from every side? 45 C is 113 F...or about the temperature of Death Valley on a typical summer day. That kind of temperature can be FATAL to humans after prolonged exposure.
- They say that the Nyrian vessel has data on 94 different slave habitats, and they establish that each habitat is fully 10 km sq in size. That means that the vessel must have enough floor space to accommodate about 1000 km sq of floor space and draw enough power to create artificial weather and support a whole biosphere full of life forms. 1000 km sq is roughly the size of Rhode Island. Voyager is roughly the size of a luxury cruise ship. You could fit hundreds of Voyagers in Rhode Island. Even if you want to be generous and assume that the slave ship had two dozen decks, each with only 50 sq km of floor space in habitats and an additional 10 for corridors, machinery and crew quarters, that would still be a vessel the size of Manhattan. Cruise ship vs. Manhattan. Yet we see Voyager fly next to the prison ship and the two appear to have sizes within the same order of magnitude. Go figure. It's a tardis! Bigger on the inside than the outside!
- How have the Nyrians never been attacked before? I'm pretty sure that is the Russians suddenly forcibly switched places with our US Navy in a base in Iceland, the entire US would go to war to get those troupes back. The Nyrians have very advanced technology...so why would they gain from stealing from lesser species who lack the means to defend themselves? No...they'd steal from species with technology that rivals theirs...but that would mean they would be begging for interstellar war. The method does not make a lot of sense.
- The show never establishes how the Nyrians were able to access Voyager's computer remotely and get info to make their habitat, steal their weapons, decrypt their access codes, learn how to use all of that alien technology etc. That's kind of important, because without some sort of explanation, we can only conclude that they have god-like powers...in which case, Janeway's subsequent ability to commandeer their displacement technology and get the upper hand makes no sense.
- What would be the point of having portals that connect adjacent habitats? Why introduce pathetic alien man at all? Except that they needed someone to show up who had knowledge of how to find the exit. *sigh*
I was able to notice all of that because, frankly, this plot has been done before, and better in other science fiction media. The added personal twist with B'Elanna and Tom is subtraction by addition. I mean, the way they interact in this episode is less annoying than several others from the third season, but it's still very hokey. I especially love the attempt at subtle *wink wink* reconciliation in the tag scene. "It got a little chilly for a while there." "Yes, I suppose it did." "Feels good to be warm again." (and both gradually flash shit-eating grins...UGH) So very...very bad. I just have to wonder if any of the Trek writers have ever been in love...because none of them seem to know how to write it with the possible exception of character-master Renee Echevarria from DS9.
All in all, this is a filler episode that feels very much like a way to kill time. It's nothing to write home about, but at the same time, it does have a ring of basic competence about it. It's rather like a number of filler action episodes you'd find between the gems on DS9. I'm not going to recommend ways to fix this one...I think they maxed out the potential of this idea for doing it in 45 minutes and it's not epic enough to want a two-parter to do more with it. Any suggestions I make for improving it would be rather like polishing a canon ball for hours while the enemy is charging your fort with ten thousand men.
There are a few plot holes, but it's a solidly par Trek script.
The basic performances are actually more than average...especially Kate Mulgrew, who handled the plot conclusion very nicely. McNeil and Dawson did what they could with their cheese-filled lines...so...no complaints here.
Not much of a message to be had here...it's a standard filler.