The Adversary (episode)

A Federation ambassador brings newly-promoted Captain Sisko orders to take the Defiant on a patrol of the Tzenkethi border, where a destabilizing coup has just taken place, but everything is not as it seems. (Season finale)

Teaser

 * "Commanders log, stardate 48959.1. It is with mixed emotions that I record this, my final commanders log. The last three years have been the most demanding, and rewarding of my career. I can only hope that the future will hold even greater challenges."

In the wardroom, Benjamin Sisko is receiving his fourth pip from his son Jake, finally becoming a captain. After being congratulated by his colleagues and as Quark serves the champagne, Federation Ambassador Krajensky informs Sisko that a coup has taken place on the Tzenkethi homeworld. Sisko is to take the ambassador and the USS Defiant (2370) to that sector to remind the Tzenkethi of the Federation's presence on nearby colony worlds.

In the Defiant's engine room, Sisko orders Chief Miles O'Brien to begin preparing the ship for combat in case the Tzenkethi start looking for trouble. As O'Brien begins his work, he hears a noise in the engine room, but sees no one.

Act One

 * "My son, the writer, thinks that I should say something profound on this occasion. He even offered to write me a brief statement. I told him I'd take care of it myself, but as it turns out, the only thing I can think of is: Begin captains log, stardate 48960.9."

In the Defiant's turbolift, Lieutenant Jadzia Dax asks Sisko if he has told Kasidy Yates about his promotion. Sisko says he hasn't, and that he barely had time to tell his father the news. Dax presses Sisko about his relationship with Kasidy, saying that the whole crew is curious. Sisko tells Dax that the next time he sees Kasidy, he's taking her to the seventh game of the 1964 World Series. Dax, amused by Sisko's response, concludes that he likes Kasidy.

Arriving on the bridge, Sisko orders the Defiant to get underway. Not long after departing Deep Space 9, O'Brien is working in a jefferies tube. He sees Doctor Julian Bashir tying in a new medical console into the main power grid, with knowledge gained from an engineering extension course he took at Starfleet Academy.

In the mess hall, Sisko tells his Chief of Starfleet security, Lieutenant Commander Michael Eddington, to keep the ambassador out of harm's way in case the Tzenkethi decide to engage the Defiant. Eddington again congratulates Sisko on his promotion, and mentions how he wanted to become a starship captain himself when he first joined Starfleet.


 * "Captains log, stardate 48962.5. We are twelve hours from the border. I haven't been in this area since the last Federation-Tzenkethi War. Being here brings back a lot of memories, most of them bad."

On the bridge, Constable Odo picks up a distress call from Barisa Prime. The colony reports that it is under attack before the Defiant suddenly loses contact.

Act Two

 * "Captains log, supplemental. We've been unable to re-establish contact with Barisa Prime. Therefore, I have no choice but to assume we are at war with the Tzenkethi."

The Defiant sets course for Barisa Prime, and Sisko asks Odo to notify Starfleet Command of the situation. Dax tries to contact the USS Ulysses, which is the closest starship, but to no avail. Odo reports that the communication system is malfunctioning. O'Brien and Dax are dispatched to make repairs.

In the jefferies tube, Dax and O'Brien find several tendril-like devices working their way into the Defiant's systems. They are protected by force fields, making them difficult to remove. O'Brien reports to Sisko that the devices are all over the ship, attached to almost every critical system. O'Brien states that these devices were not aboard when the Defiant left Deep Space 9, leading to the conclusion that someone on board is a saboteur. O'Brien reluctantly informs Sisko about his encounter with Bashir in the jefferies tube earlier. Sisko insists that he is not accusing Bashir of sabotage, but still would like to speak with him. However, Dax comes up with an idea to find out for sure who placed the devices.

On the bridge, Sisko notifies his crew of the situation. Dax scans the crew for tetryon particles, since the saboteur would have been exposed to them when the devices were installed. The senior staff tests negative, including Bashir, much to O'Brien's relief. As Dax scans Ambassador Krajensky, O'Brien talks with Bashir about their encounter in the jefferies tube, to which Bashir has no memory. The scan completes, and Krajensky tests positive. Suddenly, the ambassador changes form and escapes the bridge, revealing himself to be a Changeling.

Act Three
The Defiant cloaks and Sisko orders Dax to bring the ship out of warp, but she cannot. O'Brien cannot uncloak the ship and Major Kira Nerys reports that the ship's weapons are armed. The crew has lost control of the Defiant. Sisko orders Odo and Eddington to begin a search for the Changeling before he can do any more damage, but they are unable to locate him. Odo is confident that the Changeling is still on board, saying that he will not leave until his mission is completed. Sisko believes that the Changeling's goal is to start a war between the Federation and the Tzenkethi, speculating that the distress call from Barisa Prime was faked, and goes so far as to suggest that their entire mission was engineered by the Dominion.

Knowing that the Changeling can impersonate anyone on board, Sisko orders all non-essential personnel to be confined to quarters and sealed in with force fields, and that no one be left alone. After issuing weapons and orders to the security officers, Odo tells Eddington how he has never found it necessary to fire a weapon or take a life throughout his career. In the middle of their conversation, O'Brien calls for a security team to be sent to the engine room. Odo and Eddington arrive to find Dax unconscious. Bashir reports that she has a severe concussion and takes her to sickbay.

On the bridge, Bashir tells Sisko that Dax will be unconscious for the next couple of days, leaving O'Brien alone in his attempts to regain control of the ship. Sisko tells Kira that he cannot allow the Changeling to start a war with the Tzenkethi, and that if O'Brien can't regain control of the ship, he'll have to destroy the Defiant.

Act Four
Sisko briefs the crew on their mission: They will break into two-person teams, each one equipped with phaser rifles, and systematically sweep the ship for the Changeling. A Bolian security officer voices his suspicions that the Changeling could be anyone of them, and Sisko reminds everyone to keep their partner in sight at all times for that very reason, and orders that anyone spotted alone be escorted to the brig.

The crew begins searching the ship. Eddington asks Odo where he thinks the Changeling might be, but Odo is unsure, unable to put himself in the Changeling's position since he does not know his own people that well. Meanwhile, while Sisko and another security officer are searching a jefferies tube, the Changeling suddenly attacks them. The security officer is knocked out, leaving Sisko to pursue alone. Having been alerted to the Changeling's position, the crew moves to intercept. Arriving in the transporter bay, the Bolian security officer fires in Sisko's direction, believing that he has spotted the Changeling. Kira arrives from the opposite direction and insists that she is who she says she is, despite the fact that she and her partner have been separated for several seconds. The Bolian continuously accuses Kira of being a Changeling, and is paranoid to the point of ignoring a direct order from Sisko to lower his weapon. Just then, Odo appears and knocks out the Bolian. Eddington appears a split second later from Kira's direction, leading Sisko to conclude that any one of them could be the Changeling. Odo notes however, that Sisko is bleeding and therefore could not be the Changeling. Sisko calls Bashir and orders him to meet them in the mess hall.

In the mess hall, Bashir begins performing blood screenings of the crew. Kira and the Bolian security officer prove to be themselves, but when Bashir tests Eddington, his blood reverts to a gelatinous state. As he is escorted to crew quarters, Eddington maintains that he is not the Changeling. As Eddington is about to be forced inside the room, the adjacent door suddenly bursts open to reveal the real Doctor Bashir yelling for help. The Changeling that took Bashir's place morphs into the ventilation system and Odo pursues. A call comes in from the bridge notifying Sisko that the Defiant has entered Tzenkethi space.

Act Five
Kira reports that the Defiant is twelve minutes away from a Tzenkethi settlement. With this news, Sisko and Kira activate the auto-destruct sequence and set the timer for ten minutes. Sisko calls O'Brien in engineering and asks if he has had any progress in regaining control of the ship. O'Brien thinks he may have a way to shut down the force fields and deactivate the devices. As O'Brien works, Odo and the Changeling - who is disguised as Odo - make their way into the engine room and each one tries to prove to the chief that the other is the saboteur. O'Brien refuses to play "choose the Changeling", and has the other officer in engineering keep his phaser on both of them while he deactivates the force fields. As the force fields deactivate, the Changeling drops his disguise and attacks O'Brien and the engineering officer, leaving Odo to face the Changeling alone. As the two struggle, the Changeling tries to convince Odo to return to the Great Link, but Odo refuses and pushes the Changeling onto the warp core, fatally wounding it. Before he dies, the Changeling whispers something to Odo.

O'Brien regains control of the ship. After Sisko and Kira abort the auto-destruct sequence, the Defiant leaves Tzenkethi space.


 * "Captains log, supplimental. We've returned to the station without further incident. However, I'm concerned about my chief of security, who hasn't said a word since we left Tzenkethi space."

In the wardroom, Sisko tells the senior staff that the real Ambassador Krajensky disappeared on his way to Risa. Starfleet Security believes that he has been kidnapped, or possibly killed. Bashir asks about the coup on the Tzenkethi homeworld, to which Sisko responds that it never happened. Odo joins the meeting and informs Sisko of the Changeling's dying words: "You're too late. We're everywhere."

Memorable quotes
"You'd be surprised. People don't enter Starfleet to become commanders. Or admirals, for that matter. It's the captain's chair everyone has their eye on. That's what I wanted when I joined up."
 * - Lieutenant Commander Eddington

"Why are you protecting these solids? You don't belong with them. You belong with us. Let go. Don't you see? You've lost. It's too late for you to help them, but it's not too late to help yourself. Link with me, Odo. We can escape together."

"I... don't... think... so!!"
 * - Changeling saboteur and Odo

"Getting jumpy in your old age, O'Brien."
 * - Miles O'Brien, to himself

"Oh, JULIAN!"
 * - O'Brien, after the changeling impersonating Bashir surprises him in a Jefferies tube

"Dad, there's something I've been wanting to say to you for a long time and now that I finally have the chance, I'm going to make it short and simple. Congratulations, Captain Sisko!"
 * - Jake Sisko, at his father's promotion

"Now that you have another pip on your collar, does that mean I can't disagree with you anymore?"

"No, it just means I'm never wrong."
 * - Kira and Sisko

"''This calls for a toast!"

"That better not be from a replicator, Quark.."

"Chateau Cliant, 2303 — I already put it on your account.."
 * - Quark and Bashir

"Don't you trust me?"

"No, I don't."

"I know exactly how you feel."
 * - Kira and a Bolian Security Officer

"Captain, there's something you need to know. The Changeling, before he died, he whispered something to me."

"Go on."

"He said, 'You're too late. We're everywhere.'."
 * - Odo and Sisko

Story and script

 * The working title of this episode was "Flashpoint". In the Deep Space Nine Chronicles intro, it is stated that the episode was untitled until a contest was held and "The Adversary" was selected.
 * The producers had initially planned to do a show that had a cliff-hanger ending involving Changelings on Earth. The story was set to introduce Joseph Sisko and would take place in Starfleet Headquarters, with the end to revolve around Benjamin Sisko saying that the Founders had infiltrated the very heart of...and that was the end of the show. However, for reasons still unknown, Paramount nixed the idea, saying they didn't want a cliff-hanger ending, and so the writers came up with a story about a Changeling wreaking havoc on the Defiant instead. As Robert Hewitt Wolfe puts it, "That's when the idea of the Defiant heading inexplicably toward destruction, like the death machine that she really is, being all locked down and going like a runaway train, became the basic hook that everyone really liked." However, the Changelings-on-Earth story later served as the basis for the episodes and  the following season. (Star Trek: Deep Space Nine Companion)
 * The scene in the Defiant's mess hall where the senior officers are taking blood samples of each other to determine which one of them is the Changeling is very reminiscent of the 1982 film '. This film is based on the 1938  (writing under the pseudonym of Don A. Stuart) short story "", which contains a very similar scene. However, the writers cite neither the original story nor the Carpenter film as their primary inspiration for this episode, but rather the 1951  film adaptation, called '. That film did not feature the theme of paranoia or shapeshifters as the story or the later film adaptation did. Paranoia was something the writers were interested in exploring, as it was something rarely seen in the Star Trek universe. (Star Trek: Deep Space Nine Companion)
 * The writers decided to use the line "No changeling has ever harmed another" as an important element in this episode. This line had been heard a few times already (in, and ), and its importance would return in the fourth season finale, , where Odo receives his punishment for killing a fellow Changeling.
 * The character of Michael Eddington was deliberately set up as a red herring in this episode. The writers felt that the way actor Kenneth Marshall had portrayed the character in, and  had always implied some kind of underlying threat, so they decided to use that to their advantage in this episode. Indeed, after the episode aired, the word around the internet was that Eddington was a Changeling infiltrator, and that this was obviously going to have a bearing on the upcoming season. Upon hearing this, the writers decided that they would never make Eddington a Changeling.(Star Trek: Deep Space Nine Companion) Later on, it would be revealed that Eddington was a threat, but not in the manner people expected: he was a member of the Maquis who would eventually betray Starfleet.
 * Sisko's opening log entry was not in the final draft shooting script.

Production

 * The fight between Odo and the Changeling at the end of the episode was extremely complicated to put together due to all the morphing effects. Producer Steve Oster points out that there are more morphing effects in this short scene than in the entire third season. According to actor Rene Auberjonois, after principal photography was completed, all the cast were allowed to leave except himself and Lawrence Pressman. He explains that during the main shoot, he and Pressman had filmed the scene as normal, but to make sure the effects would work properly, each of them then had to re-enact the scene separately, looking at a monitor and matching their movements exactly. (Star Trek: Deep Space Nine Companion) There are actually some clips of both actors shooting the fight without the other present in the Deep Space Nine Chronicles intro to this episode.
 * The scene when Krajensky morphs into a Changeling and escapes through the vent is one of visual effects supervisor Glenn Neufeld's favorite shots from the entire seven years of DS9.

Reception

 * Ronald D. Moore is a big fan of this episode because he considers it to be very un-Star Trek; "It really appealed to me on this sort of visceral John Wayne level. There's a monster on the ship, it's after us, and we're gonna hunt it down and kill it. We're not gonna negotiate with it, we're not gonna worry about whether it's sentient, we're not gonna play any of the usual Star Trek games with it. It's just, 'Find and kill the monster.' There was something very pure about that show." (Star Trek: Deep Space Nine Companion)
 * Ira Steven Behr sees this episode as an important step in the show's movement towards serialization, which would reach a peak in the six-episode arc which opened season six and the nine-episode, ten-hour arc which acted as the finale of the series itself; ""The Adversary" was the first one where we really knew we were going to be starting to get the S-word, serialized, just a tad. In spite of all the finger-wagging and knowing we weren't supposed to, it was just a little bit, a little bit." (The Birth of the Dominion and Beyond, DS9 Season 3 DVD special features)

Trivia

 * This episode marks the first appearance of several new sets aboard the Defiant, namely main engineering, the mess hall and the extended corridor set.
 * According to the Star Trek: Deep Space Nine Companion, the rifles used in this episode are the first rifles ever seen in Star Trek which actually have a trigger.
 * In the teaser for the episode Sisko is promoted to captain, however in the opening credits of the show he is still credited as "Commander Sisko". This is the last episode to credit Sisko as a commander. It is also the last time Sisko is seen with hair and it is the last episode to have the opening credits from Season 1.
 * This episode marks the last time Alexander Siddig is credited as Siddig El Fadil as an actor. As a director, however, he remains credited as Siddig El Fadil for.
 * According to Jadzia Dax, there are 47 people on board the Defiant in this episode.

Video and DVD releases

 * UK VHS release (two-episode tapes, CIC Video): Volume 3.13,.
 * As part of the DS9 Season 3 DVD collection.

Main cast

 * Avery Brooks as Captain Benjamin Sisko
 * Rene Auberjonois as Constable Odo and Changeling saboteur
 * Siddig El Fadil as Doctor Julian Bashir and Changeling saboteur
 * Terry Farrell as Lieutenant Jadzia Dax
 * Cirroc Lofton as Jake Sisko
 * Colm Meaney as Chief Miles O'Brien
 * Armin Shimerman as Quark
 * Nana Visitor as Major Kira Nerys

Guest stars

 * Lawrence Pressman as the Krajensky and Changeling saboteur
 * Kenneth Marshall as Michael Eddington
 * Jeff Austin as a Bolian security officer

Co-star

 * Majel Barrett as the Computer Voice

Uncredited co-stars

 * Sam Alejan as a medical officer
 * Ivor Bartels as a security officer
 * Jeff Cadiente as an operations division ensign
 * Tory Christopher as a medical lieutenant
 * Kathleen Demor as a security officer
 * Randy James as Jones
 * Mark Lentry as a command division lieutenant commander
 * Dennis Madalone as a Human security officer

Stand-ins and stunt doubles

 * Tom Morga as stunt double for Jeff Austin
 * Unknown stunt performers as
 * Stunt double for Rene Auberjonois
 * Stunt double for Nana Visitor
 * Photo double for Rene Auberjonois