Nutshell: The story is fairly derivative, but the presentation and characterization makes it worthwhile. A slow, pleasant outing.
When Odo arrests a woman for illegally accessing station information, she reveals to him her troubles: She is looking for an Idanian agent who was supposed to meet her on DS9—someone who could help her with her big problem. The woman's name is Arissa (Dey Young), and she is a member of the nefarious, covert Orion Syndicate under an unseen, all-powerful commanding officer named Draim. Arissa hates the dreadful implications of her job and needs a way out of the Syndicate. But very few people who leave the Syndicate live long to tell about it; they're usually assassinated with prompt skill. And no one opposes the wishes of the infamous Draim.
In the episode's opening minutes, the Idanian agent Arissa is supposed to meet is vaporized by two Orion Syndicate thugs (who, unlike the Cardassians' Obsidian Order, hardly show the grace that would exemplify such a devious organization). When Odo finds evidence of the murder, Arissa looks to Odo for protection and her "way out." Odo, being the Changeling with the big heart, offers whatever help and protection he can provide so that Arissa can live to testify against Draim and send him to prison—not an easy task. In the meantime, Odo comes to respect Arissa's courage and finds himself falling in love with her.
"A Simple Investigation" makes use of a tried-and-true premise—that of a person in trouble who falls in love with the one who protects her. This premise is one that has been used in cinema, television, and second-rate novels so many times that the plot I just described probably seems mostly derivative.
Well, yes, the basic plot is derivative, and, at times, predictable as well. It hardly matters. Rene Echevarria (who I'm endeavoring today to label the best and most prolific Odo writer) supplies the script with the necessary, yet simple, character details and dialog that turns the episode into a slow, quiet, pleasant winner. This is yet another good Odo outing.
Watching "A Simple Investigation" reminded me of last season's also-quiet "Crossfire." Both are small Odo pieces written by Echevarria that provide minimal story substance that wisely plays secondary to amiable characterization. Neither show features anything that stands out as spectacular or instantly attention-grabbing. Both feature perfunctory plots. But, rather, the point of both is to simply provide a slow exposition on Odo's human condition within his identity of a Changeling.
One (although not the only) reason Odo is so intriguing is because he's the DS9 version of the Trekkian character who exists outside the "human condition" to make wry observations about humanity. Every Trek series has one. On the original series it was Spock; on TNG it was Data; on Voyager it's the Doctor. What makes these characters interesting when they're inserted into romance premises like this one is that it puts us, as viewers, into the intriguing mindset of trying to experience vicariously what it is to be human. To do this we attempt to get into Odo's mind and identify with what it means to not be human.
That's probably the deepest thing I can say about this episode, because there really isn't all that much to say about this show—at least, not thematically. "A Simple Investigation" is a simple show, and it's decent that way. I don't think I would look for something like this every week on DS9, but it certainly isn't a problem occasionally.
Aside from the Trekkian Human Question, the other big thing this episode gets right is the chemistry between Odo and Arissa. Chemistry is important in these types of shows, and "A Simple Investigation" features Odo at perhaps his softest in quite a while, yet he is still well within the boundaries of the character we know so well. Everything Odo does seems genuine and heartfelt; his attraction to Arissa never comes across as forced or insincere. By the same token, Arissa is pulled off skillfully by Dey Young, who has an aura of charisma about her that seems to give a reason for why Odo is so taken by her. The personalities here are on-target, and that's worthy of praise for both Auberjonois and Young.
Naturally, I wouldn't be doing my job as a reporter if I didn't comment on the inevitability of these two characters ending up in bed together. Although the implications of a lovemaking Odo had me wondering just how human Changelings can truly be (one question still remaining is "Did Odo morph his clothes off?", but never mind) I think it's also important to note that Odo has generally been as "solid" or as "human" in physical form as any given episode requires him to be. (This also explains, for example, why he can be knocked unconscious when hit on the head, as in "Vortex.") I'm not about to argue. It's the emotional aspects of the situation that are important, and I think the show handled them pretty well. Sure, some of the dialog turned repetitive and even obvious at times, but it was sweet and innocent because, well, Odo's just sweet and innocent in this sort of situation.
Quick aside: While we're on the subject of the (implied) sex in this episode, let me just make a quick juxtaposition: Unlike in the preposterously dumb and superficial Voyager offering, "Favorite Son," from a few weeks back, "A Simple Investigation" handles the sensuality with a tenderness and commitment that makes it worthwhile, rather than just laughable. Lisa Klink could take some pointers from Echevarria, if I may be so bold.
(On a totally unrelated note, Echevarria scores a few points with the amusing revisit to the "double-O-Bashir" program. It's nice to see that the crew decided to make the best of the rather weird situation that was "Our Man Bashir." Could all this subsequent role-playing have been Bashir's wild idea?)
So what about the plot of "A Simple Investigation"? Who cares? It serves its purpose by just sort of being there, and being out of the way when appropriate. Most of the plot revolves around the need to find out what mysterious information is contained on the data crystal that Arissa obtains early in the episode. The show's ending is Fairly Standard Espionage Stuff. It turns out that Arissa is really an undercover Idanian who had her memory wiped (and put onto the mysterious crystal) as a way of making her the best person (a person unaware of her motives) to infiltrate and expose the evil Draim and the Orion Syndicate.
Naturally, as these stories go, the plot twist is the catalyst for ending the relationship—in this case Arissa is not who she thinks she is, and when her memory is restored she realizes that she's married. I saw that one coming about a mile away, but it works okay here, nonetheless. We all knew that Odo's first relationship with a woman had to end in heartbreak. At least this way it was due to extreme circumstances. It could've turned out that Arissa was a spy and was really manipulating Odo—that would've been cruel, and I'm glad Echevarria didn't choose that route.
I don't really care much that the plotting is derivative; these machinations are not the point of this episode. The point is Odo's romantic situation, which proves intriguing most of the time, sincere all of the time, emotional at the end, and well-performed throughout.