"Necessary Evil" is a wonderful episode of Deep Space Nine. Peter Allan Fields shows that he is the premiere writer for the show, especially for Odo (Rene Auberjonois) and Kira (Nana Visitor). He knows their characters so well. He has an ear for dialogue, the plot is wonderful, and the mystery is intriguing. Everything comes together to make one stellar episode. If "Duet" is the heart of the show, "Necessary Evil" showcases the soul. The friendship between Kira and Odo is one of the cornerstones.
Quark (Armin Shimmerman) is hired by Vaatrik Pallra (Katherine Moffat) to go into her dead husband's old store back on Deep Space Nine and find a box that is hidden there. Quark, being the greedy soul that he is, opens it, and is shot for his trouble. Vaatrik knew he would do it and sent somebody to watch him. Thanks to Dr. Bashir (Siddig El Fadil), Quark is saved, and Odo begins an investigation into what happened. Rom (Max Grodenchik) leads Odo to the chemist's shop, which takes Odo back to the Cardassian occupation. Vaatrik's husband had been murdered and Gul Dukat (Marc Alaimo) asks Odo to find out who did it. Kira is one of the main suspects, but she has an alibi. A murder from five years ago may reach forward to the present and destroy a friendship.
I normally don't talk about the direction of an episode, though Deep Space Nine usually has a talented director at the helm. This time, though, I have to. James L. Conway does a masterful job with the transitions between the present day and the past, especially the first. When Odo opens the door to the abandoned chemist's shop, the scene suddenly changes time periods as the door opens. It's a masterful shot, and most of the other transitions are almost as good. The set design is also wonderful, this being the first time we've seen the station as it was under the occupation. Everything is dark, the mood is depressing, armed guards are everywhere and the Bajorans walk around like a beaten people. The camera work is great, capturing all this in the background even as the foreground has a standard questioning scene. It's all wonderfully done. Enough can't be said about the strength of the story or the dialogue either. The main episode (after the teaser) begins with a wonderful security log entry by Odo, where he goes on about humanity's obsession with keeping records and him saying that Starfleet doesn't trust his "fully adequate" memory to suffice. He then makes his entry. "Everything's under control. End entry." It's a great laugh, but also a great device to get Odo's thoughts across to the viewer as he investigates this murder that's clawed at his mind for the last five years. The scenes with Rom & Quark (and later, Rom & Odo) are funny in their own way, but they don't really fit the tone of the episode. Rom's going back and forth between fear for his brother and fear that his brother won't die (he'll inherit the bar if Quark dies) are very amusing, and would work better in a different episode. They're a little too slapstick for this one, though they do break the tension a little bit. We also (*shudder*) get to hear Rom scream a few times. Definitely not a plus.
That would be the only misstep, though. Odo gets to demonstrate his observational skills (did he take a few lessons from Sherlock Holmes?) as he deduces when people are lying to him. His investigation on the station five years ago was very thorough and he faces the pressure from Dukat to find the name of the murderer as soon as possible. The dialogue between Dukat and Odo is almost perfect, with Alaimo being his normally smarmy self. Auberjonois also plays the scenes with Dukat perfectly, but he is definitely at his strongest when he's compared to his present-day self. Currently, he's confident and direct. Back then, he wasn't sure of himself, making his way on the station by settling petty disputes for the Bajoran slaves. He speaks a bit hesitantly, he looks down a lot, he's unsure of everything. It's completely unclear why Dukat would pick him for this job, as it's obvious that he's lying when he gives his reasons. We do find out at the end why he would, and the revelation is marvelous.
Even better are the scenes between Odo and Kira. Their friendship has often been portrayed in previous episodes, but it's never been a centerpiece. It's the glue that's held them together but it's never been the basis for a show. This time, however, it's showcased. When this murder comes to the foreground again, she's obviously uncomfortable around it. She's by the book whenever she's with Odo. The final scene between them is simply the best scene since "Duet."
The other characters don't have much to do, but that's ok. They get a token scene, but none of them are gratuitous. The only one we don't see is O'Brien, but that's because there was no need for him to get involved. The doctor has to take care of Quark, Odo has to ask Sisko (Avery Brooks) for permission to have Vaatrik brough on to the station. They each play their parts and then get out of the way. Quark is put to his best use in a long while as the catalyst that brings it all together (though you would think he'd have a breaking and entering charge against him when he woke up).
This is simply a beautiful episode from start to finish. The only problem is that there is no fallout from this episode in subsequent episodes. Still, that's not a strike against this one. Sparkling dialogue, excellent sets and costumes, direction, acting. You name it, this episode has it. And best of all, you don't really need to know anything about the show to enjoy it. This is one of the best Deep Space Nine episodes ever.
Rom: "Wait a minute! You're not suggesting that I…"
Odo: "I've had my eye on you for a long time, Rom. You're not as stupid as you look."
Rom: "I am too!"
Dukat: "Have you ever seen a dead man before?"
Odo: "Yes. In your mines."
Dukat (scoffing): "Oh, those are *casualties*. This…is murder."