Starring Avery Brooks, Michael Dorn and Nana Visitor
Created by Rick Berman and Michael Piller
Based on 'Star Trek' created by Gene Roddenberry
To this end, Captain Sisko (Avery Brooks), Chief O'Brien (Colm Meaney), Lt. Commander Worf (Michael Dorn) and Constable Odo (Rene Auberjonois) go undercover in the Empire with the help of a stolen Klingon ship captained by Dukat (Marc Alaimo). There, they hope to infiltrate a gathering of warriors to expose the Changeling in public, and hopefully bring an end to the Klingons' war with the Federation.
But even though they do this great service for the Empire, Gowron tells them it is too late to stop the conflict. As the Federation faces increasing losses to the vicious Klingons, Sisko knows the Dominion is just waiting to pick off their remnants. Frustrated by his peoples' subjugation at the hands of the Klingons, Dukat forms an alliance with the Dominion, giving them the in they need to begin moving massive numbers of troops and equipment into the Alpha Quadrant.
In response, Sisko enacts a bold plan to mine the entrance to the wormhole, cutting off the Dominion supply lines from the Gamma Quadrant. It is an act that could lead to war.
Season Five is another fantastic season for "Deep Space Nine." Though the season opener isn't all that great, the very next episode, "The Ship" (also the series' 100th), is rather excellent. In it, the crew is trapped aboard a downed Jem'Hadar vessel, which they hope to claim salvage. Outside, another Jem'Hadar squad wants something that's in the ship. Sisko faces off against the Vorta leader, and ultimately the two realize that if they'd simply trusted each other, lives wouldn't have been lost. But they're so incapable of doing so, that the ending is inevitable.
The season overall is darker in tone, as evidenced by the episode above. One thing fans have often decried about 'Deep Space Nine' is that it often lacks the optimistic tone of the original series or 'The Next Generation,' in which the humans are happy people who bring enlightenment to the galaxy. The characters of 'Deep Space Nine' on the other hand are often flawed, and more complicated, although they are also usually trying to do the right thing even if they fail to do so in the end. Their hearts are in the right place, and they constantly struggle to be better.
One episode often pointed at in this context is "For the Uniform" - in this episode, Sisko tracks Maquis traitor Michael Eddington (Kenneth Marshall) who has begun using biological weapons to take back colonies from the Cardassians in the DMZ. As Sisko becomes more obsessed with catching Eddington, he becomes more reckless, and even resorts to using biological weapons himself in order to poison the atmosphere of a Maquis colony and force Eddington to give himself up. It's a pretty fascinating look at the Sisko character, how deeply he holds his beliefs in Starfleet and how wounded he was by Eddington's betrayal.
This darker tone for the series is also what makes it so excellent. It's not afraid to go to places with its characters that the other 'Star Trek' shows wouldn't. In "The Darkness and the Light," a serial killer is murdering members of Kira's (Nana Visitor) old resistance cell. The episode is rather frightening in its technical production, as the killer seems nearly unstoppable, and leaves chilling messages for Kira each time he kills one of her friends. The episode's climax features an excellent performance by Randy Oglesby, who would later play Degra on 'Enterprise', as the half-crazed killer who thinks he's out getting some kind of warped "justice."
Similarly, "Empok Nor" sends O'Brien, Nog (Aron Eisenberg), Garak (Andrew Robinson) and some red-shirts off to an abandoned Cardassian station where Garak begins to turn against them thanks to exposure to some kind of alien compound. This episode, too, is dark in more than just the literal sense. Once Garak becomes fully unhinged, Robinson's performance brings a thick layer of menace to the proceedings.
Ultimately, the season finale "Call To Arms" caps things off in an incredible manner. Sisko's plan to mine the wormhole is long overdue, and his conversations with Weyoun (Jeffrey Combs) are fantastic. The entire episode has a feeling of release, as though this is what the entire show has been building toward for five years. And to an extent, that's true. Ever since the Dominion was first mentioned early on in Season Two, things have been headed in this direction. Even to this day, dragging the benevolent Federation into a war over an extended storyline is unheard of in 'Star Trek', which makes 'Deep Space Nine' not only awesome... but totally unique.
But the episode is also filled with excitement for future episodes. The last shot of the season is as energizing and tantalizing as it gets, with the Defiant joining a massive fleet of Federation and Klingon ships ready to do battle against the Jem'Hadar and the Cardassians.
Season Five is darker than ever before, but it also presents a show that is more complex and fascinating than ever before. With its expansive cast, multiple long-running storylines, and fantastic special effects, 'Deep Space Nine' takes its place at the top of the 'Star Trek' heap. It's no mere sci-fi show, but a political thriller set in space... and all the better for it.