So, er, the episode I missed last time - they received an SOS, discovered that the Dominion was massing a fleet near the wormhole, Garek and Worf ended up in a Dominion internment camp and found the real Martok and Bashir, who'd also been replaced by a Changeling, and then the Dominion fleet had started flooding through the wormhole.
Got that? Good!
With the help of Dukat, they prepare to defend DS9. However the Dominion ships ignore and sod off in the direction of Cardassia. Dukat joins the Dominion fleet, revealing that he's actually been secretly negotiating with the Dominion and Cardassia is joining up.
Bashir shows off the secret compartment in their cell which leads to a jury-rigged communication device. They decide that Garek should modify it to contact the runabout and beam them all off. The Vorta in charge of the camp gathers the prisoners together, and lets them know that the Cardassians are going home. Unfortunately Garek isn't included in the prisoners being released because he's not popular with the new head of the Cardassian government - Gul Dukat.
Meanwhile Dukat is giving a speech about their new alliance with the Dominion and promises to wipe out all Klingons and Maquis within the Cardassian empire borders. Kira promises to kill Dukat next time she sees him. FakeBashir suggests there's a Changeling on board and organises blood screenings.
Garek continues trying to modify the communications array. The Gem Hadar visit the cell to pull Worf and Martok out so that Worf can have a training fight with a Gem Hadar soldier. Bashir is concerned about Garek's health, but the Cardassian's keep to keep modifying the array. Worf wins his fight, only to be told that the soldier was the youngest of them.
Kira and Ziyal, Dukat's daughter, look out at the wormhole and wonder about Dukat's actions. A bunch of Klingon warships from Cardassian space arrive at DS9 with wounded. Sisko suggests to Gowron that he might want to revisit a peace treaty with the Federation. Gowron accepts. FakeBashir goes and hops in a runabout.
Worf's fighting goes on. Score so far: Worf 5, Gem Hadar: 0. Bashir says Worf has several broken ribs and if he continues fighting tomorrow, may die. Garek, meanwhile, is talking to himself and suffering from claustrophobia. A while later, the other prisoners hear banging, and Bashir finds Garek having a panic attack. Unfortunately he's the only one of them with the technical ability to alter the array.
Kira reports the Changeling intruder's been messing with a replicator. Dukat contacts Sisko and tells him that he should try to convince the Federation to join the Dominion, and that he intends to retake DS9. Sisko's response: Bring it on.
Worf manages to survive the next day's fights. Garek says he's ready to continue with his work on the communication array.
O'Brien tells NotBashir that Keiko and the kids are safely away. NotBashir says he's ordered in some new darts. Quark grumbles that if the Dominion takes over the station he'll be out of business because the Gem Hadar and Changelings don't eat, drink or shag. Ziyal tried to cheer him up by suggesting maybe the Vorta are gluttonous drunkard sex maniacs.
Garek continues to talk to himself. Worf faces the head Gem Hadar in combat. The Gem Hadar come looking for Garek so they can execute him.
DS9 gets ready to defend itself against the Dominion. A bunch of Romulan ships unexpectedly turn up to help.
Worf, meanwhile, is losing his fight. The Gem Hadar soldiers locate the hidden passage in the cell, but the prisoners manage to kill them. Though Worf is losing his fight, the Gem Hadar yields cause he doesn't want to kill Worf. The Vorta says to shoot both combatants, but at that point Garek succeeds and everyone beams out to the runabout.
O'Brien and Sisko are confused by the lack of a Dominion attack force - they're reading warp signatures everywhere, but can't detect any ships. Bashir's message reaches the station, and they detect NotBashir's runabout on course for the sun. The Defiant sets off in pursuit, detecting that there's a bomb on board which could send the sun nova. They manage to intercept it in time. O'Brien discovers the warp signatures have vanished - a trick.
After the prisoners return, O'Brien wonders how he hung around with a Changeling for four weeks and didn't realise. Dax is happy to see Worf. Gowron says he wants a permanent Klingon force on the station and Sisko nominates Martok as their commander. Dukat contacts Sisko to congratulate him on foiling the Dominion plan and issue more veiled threats.