Nutshell: It's amazing that a premise this outlandish can work, but it somehow does, though not without some significant shortcomings.
A very bizarre transporter mishap results in "symbiogenesis" and merges Tuvok and Neelix into a single individual who appropriately names himself "Tuvix" (after briefly considering "Neevok" as a name). Initial studies by Doc reveal that separating the two may not be easy—or even possible. Tuvix must subsequently face the possibility of his unique and permanent existence, realizing that the individuals Tuvok and Neelix may forever be lost.
We've had lots of high concept stories this season, from "Dual Voyagers must outwit the Vidiians!" to "Paris accelerates beyond warp ten and turns into a mutant!" to "Harry Kim travels to a parallel universe Earth!"—but "Tuvix" takes the cake with its single-sentence pitch in which "Tuvok and Neelix are combined!" Is high concept bad? Certainly not. Such shows can be interesting, new, and compelling so long as the single sentence is backed with good storytelling. Of course, if the show fails to deliver beyond its starting point, it simply becomes what may best be called a low concept—a bright idea that goes nowhere.
"Tuvix," fortunately, supplies some human writing behind its bright idea, and the show overall is better than I expected. While there are times when the episode wanders (there's an occasional sense that the creators are gambling that this weird combo-character walking around the ship will automatically prompt awe and wonder from us), "Tuvix" is mostly a character show. And it's a decent character show, even if a bit uneven.
The show could've centered around whether or not Tuvok and Neelix could be restored (which is a foregone conclusion), but fortunately, the real core of the episode centers around the consequences of doing just that. You see, Doc doesn't find a cure at first—it takes him over two weeks. And in this time, Tuvix begins developing his own personality and emotional ties. He takes Tuvok's post as tactical officer, replaces Neelix as head chef, and tries to resume a relationship with Kes.
Most of the characterizations are fairly good. There's a nice scene between Janeway and Kes that works pretty well, even if the subject matter (the obvious coping-with-death topic) isn't all that impressive. At the same time, Tuvix's plight for individuality is certainly agreeable. Tuvix is a surprisingly likable character. Tom Wright's performance is not always on-the-money, but he does do a respectable job of combining the two unlikely personalities together—not an easy task. There's a sense of both Tuvok and Neelix in Wright's gestures and demeanors. It's rather strange—and quite interesting.
And by the end of the show, Tuvix becomes a character all in himself. I actually found myself thinking of him as an individual and not a combination of two other characters. This is a respectable feat on the part of director Cliff Bole; since the end of the show centers around the question of whether or not Tuvix has individual rights, it's important that the audience have sympathy for him.
But despite the character-driven strengths in "Tuvix," this episode doesn't entirely click. There are some problems with how this show unfolds. The bottom line of "Tuvix" doesn't really center around whether or not Tuvok and Neelix will be restored, yet the first four acts still tend to revolve around this question. From Kes' coping with the loss of Neelix to the Doctor's frantic search for a cure (which, naturally, involves the usual technobabble and DNA tricks that border on total incredulity), there seems to be too much emphasis on the question of how to restore Tuvix back to two people.
Then in the fifth act, the show does a complete 180 when Doc finds a miracle cure and the story abruptly shifts focus to the morality question of killing Tuvix to save Tuvok and Neelix when Tuvix passionately expresses a desire to remain "joined." This part of the show is especially interesting, but the execution doesn't hold up very well.
For one, I think Tuvix is a little too adamant on living. Wouldn't his logic see both sides of this complex issue? The writers make Tuvix's position on this argument a little more concrete than it probably should've been. The lack of subtlety in his character may be explained by the bigger problem here—the way this whole argument is jammed into the final act of the show. It would've been much more prudent to dedicate more of the show to this argument rather than spending so much time on Kes' coping-with-death issue and Tuvix's initial fish-out-of-water dilemma. While all three elements of the show are certainly relevant, only Tuvix's sacrifice really holds any lasting impact. Unfortunately, very little of the episode focuses on the most important aspect.
Janeway's decision to force Tuvix to submit to a procedure that would kill him in order to save two crewmen is a powerful turn of events. And the subsequent fact that the Doctor will not harm Tuvix against his will leads Janeway to actually carry out the procedure herself—and having to live with the consequences of what Tuvix labels "murder." This is all very interesting, but it also brings up a number of troubling questions that the episode does not begin to address. This is too bad—if the show had found its focus on this issue sooner, it could've been a compelling installment. As the episode stands, it feels unfinished, uneven, and underutilized.
"Tuvix" is an entertaining character show that tries to say something, but overall it isn't what I would call an excellent or even impressive show. It's a missed opportunity in some ways, while it works in other ways. Three stars seems about fair, I guess—but just barely three stars.
On a minor, unrelated note, I didn't like the teaser at all. I'm getting sick of Neelix's badgering of Tuvok over the fact that he is unemotional. It's getting very, very, very old. Why can't Neelix just accept Tuvok for what he is? For compensation of this scene, I think I'll dig up my tape of "Meld" so I can watch Tuvok strangle the annoying little Talaxian again.