The Dominion is sending new reinforcements through the wormhole on a weekly basis. Letting them enter puts the whole Alpha Quadrant at risk, which is why Sisko decides to mine the entry to the wormhole, so that no new Jem'Hadar ships can get through. Weyoun warns Sisko that the Dominion will not let them go through with this plan, and a war between the Federation and the Dominion looks inevitable. Sisko uses his leverage as the Emissary and convinces the Bajoran government to sign a non-aggression treaty with the Dominion, as this is the only way Bajor will avoid the upcoming war. The B plot of the episode involves Leeta and Rom preparing for their wedding. The forthcoming Dominion attack forces them to have the wedding ahead of schedule, and any chance of marital bliss they might have had is cut short, as all Bajorans are evacuated from the station. The sole exception to this is Kira, who willingly stays on Deep Space Nine, as do Odo, Quark, Rom...and Jake.
- Aww, Look! They Really Do Love Each Other: After berating Rom for sending is wife away but staying behind, Quark kisses him on the head while he works to ready the defense grid.
- Big Badass Battle Sequence: An appropriate way to start a war.
- Breaking the Fellowship: The main characters are separated into two groups: those who are forced to leave Deep Space Nine (Captain Sisko, Dax, Worf, O'Brien, Bashir, Nog, Garak), and those who stay behind on the station (Kira, Odo, Quark, Rom, Jake Sisko).
- Garak recalls the time he and Dukat fought side-by-side against the Klingons and how, for a moment, he considered shooting Dukat In the Back.
- Sisko orders that Deep Space Nine be disabled before being taken by the Dominion, similar to how the Cardassians had the station crippled before Starfleet took it in the pilot episode "Emissary".
- Sisko pushing for Bajor to sign a non-aggression pact is an outgrowth from his prediction in "Rapture".
- Sisko leaves his baseball behind in his office as a message that he'll be back, just as he did in the second season's "The Siege".
- As the Dominion and Cardassians prepare to board the station, Quark yells for someone to find him some yamok sauce.
- Comically Missing the Point: When Leeta complains about a possible wedding outfit being "two handkerchiefs and a loincloth," Rom suggests losing the handkerchiefs.
- Continuity Nod:
- In a previous episode, Sisko had a vision that told him that if Bajor joined the Federation, Bajor would be destroyed. This episode shows why; here, an independent Bajor signs a non-aggression pact with the Dominion to protect itself, something that could never have happened if Bajor was a Federation world.
- Kira mentions that she learned that Odo has feelings for her a month ago. "Children of Time" aired the previous month.
- Cut Phone Lines: Odo asks Kira to terminate subspace communications from the station in order to prevent security breaches.
- Darkest Hour: Between numerous Dominion warships passing through the wormhole and the Romulans signing a non-aggression pact, Sisko believes they have to act now before it's too late.
- Deal with the Devil: Sisko uses his status as Emissary and Starfleet Captain to convince the Bajoran government to sign the non-aggression pact with the Dominion, as it is the only way Bajor can escape the coming war.
- Delaying Action: The point of the battle is to buy the Defiant enough time to lay the Space Mines, as well as to draw the Dominion fleet away from a combined Federation / Klingon attack on one of their shipyards. Once that's done, Sisko orders a Tactical Withdrawal.
- The Dreaded: The Teaser rattles off several powers who would rather sign non-aggression pacts than risk a Dominion invasion.
- Sisko leaves his baseball in his office as a message that he'll be back.
- When asked about the possibility of reinforcements, Sisko says that Starfleet's attention is needed elsewhere. Later, before leaving, Sisko reports that Starfleet and Klingon ships destroyed shipyards at Torros III while the Dominion was attacking the station.
- Gunship Rescue: Who says there's never a Klingon around when you need one?
- Heroic Vow: Sisko's final message to those he's leaving behind:"Your sacrifices, our sacrifices, made this victory possible, but no victory can make this moment any easier for me. And I promise, I will not rest until I stand with you again... here... in this place where I belong."
- I Choose to Stay: Jake stays on DS9 (or, as Dukat calls it, Terok Nor) to carry out his reporting duties. Sisko is not happy.
- I Know You Know I Know: Sisko is well aware that the brief "negotiation" after Sisko's refusal to remove the mines is completely meaningless, and that the Dominion are going to attack the station. The only question is whether or not Weyoun realizes that Sisko knows.
- Lock-and-Load Montage: The middle of the episode is taken up by battle preparations, closing with the activation of Deep Space 9's weapons arrays as the Dominion fleet approaches.
- It's a Long Story: Kira tries using this to avoid explaining to Dax why she and Odo are so awkward around each other, but Dax makes her explain.
- Loophole Abuse: Dukat tries getting around the non-aggression pact by stating it was signed by the Dominion, not Cardassia. Weyoun quickly yanks the leash a little by reminding him Cardassia is part of the Dominion now. And Bajor is off limits.
- Nothing Is the Same Anymore: After three seasons of anticipation, the Federation is now officially at war with the Dominion. Bajor is forced to sign a non-aggression treaty with them, and Federation troops withdraw from Deep Space Nine. At the end of the episode, the Cardassian/Dominion army boards the space station, and it once again becomes Terok Nor, lead by Gul Dukat.
- O.O.C. Is Serious Business: When Weyoun arrives to try and get the minefield taken down, he's dead serious. No fake smiles or compliments. Just a straight threat.
- Pet the Dog: Weyoun is dead serious about Bajor's non-aggression pact with the Dominion, sternly warning Dukat that he expects Cardassia to honor it.
- Pyrrhic Victory: Gul Dukat successfully retakes the station, but fails to stop the minefield from being activated while a Dominion shipyard is destroyed elsewhere. Weyoun also notes that 50 ships were destroyed in their effort to take the station.
- Relationship Upgrade: Odo tells Kira that he's been thinking about this, but he's decided not to during the current crisis.
- Salt the Earth: Kira executes Sisko's program to disable the station once Starfleet has left. Justified, as it denies the Dominion any intelligence it could've obtained from the Federation computers (and lets Sisko and Kira flip the bird to Dukat).
- Scotty Time: Dax and O'Brien repeatedly say they need more time to lay the minefield. Naturally, they get the job done.
- Shout-Out: Rom's speech to Leeta about getting her off the station is a reference to Casablanca.
- Stock Footage: A lot of the shots of DS9 readying and firing weapons are reused from "The Way of the Warrior", with the Klingon ships replaced with Cardassian and Dominion ones.
- Tech Marches On: In-Universe. After capturing a Jem'Hadar fighter, Starfleet was finally able to adjust their shields to protect against Dominion weapons.
- Teeth-Clenched Teamwork: Dukat clearly wants to try to use the Dominion to his own ends and thinks he's only putting up with them as long as it takes to make Cardassia great again, meaning defeating and destroying the Federation and Klingons and retaking Bajor. The Dominion, in the person of Weyoun, has other ideas and sternly informs him that he will honor the non-aggression pact. Dukat grudgingly agrees, with an unspoken "for now" evident in his tone and the glance he gives to Damar.
- That Came Out Wrong: Rom asking Sisko to perform his and Leeta's wedding:"Will you marry me? I mean, us? I mean...will you perform our wedding?"
- This Explains So Much: Played for Laughs when Kira admits to Jadzia that Odo has a crush on her.Jadzia: That explains a lot.
Kira: What do you mean?
Jadzia: ... I don't know, really. It just seemed like the thing to say.
- Underestimating Badassery: Federation shields had always proven useless against Dominion weapons, but that's not the case anymore. Weyoun is stunned. Justified thanks to the fact the Federation had been handed a Jem'Hadar fighter nearly intact by another Vorta in "The Ship".
- We Will Meet Again: Sisko left his baseball behind in his office.Weyoun: What is that?
Dukat: A message from Sisko.
Weyoun: I don't understand.
Dukat: He's letting me know he'll be back.
- Wham Episode: After three years of waiting, the Alpha Quadrant is finally at war between the Dominion and Cardassia against the Federation-Klingon Alliance.
- Wham Shot: The final shot of the episode shows the Defiant and Martok's Bird-Of-Prey flying off into space...where they meet with what looks like the entire combined fleets of both the Federation and the Klingon Empire! The instant you see this, you know just how serious things have gotten!