With the Bajoran wormhole collapsed, Sisko struggles for a way to contact the Bajoran Prophets. The Romulans receive permission from the Bajorans to open a military hospital on the moon Derna. General Martok offers Worf an opportunity to gain admission to Sto'Vo'Kor for Jadzia.
A new Dax appears on the scene. Sisko's quest leads him to the truth about his existence. The discovery that the Romulan hospital is heavily armed leads Colonel Kira to set up a blockade of Derna. Bashir, O'Brien and, surprisingly, Quark join Worf and Martok on a dangerous mission to destroy the Dominion shipyard.
Everyone who knew Jadzia Dax reacts strongly to Ezri Dax's presence, particularly Worf. Garak suffers from bad attacks of claustrophobia.
Sisko must train his staff to play baseball when the Vulcan Captain Solok, an old rival of his, challenges Sisko to a game while his ship is being repaired.
Bashir falls for a genetically enhanced patient, Sarina Douglas, that he brought out of a catatonic state using an experimental medical procedure.
A Vorta defector, Weyoun-6, gives Odo valuable information in exchange for asylum. Weyoun-7, the next clone in the series, pursues them. Nog engages in a series of barters to get a Graviton Stabilizer for Miles.
Kor (Ep 2.19, "Blood Oath" & 4.9, "The Sword of Kahless"), an aging Klingon hero, asks Worf to find him a battle assignment. Martok plans a "cavalry raid" of five birds of prey, hitting several key targets behind enemy lines to throw them off balance.
Sisko and crew relieve Starfleet troops under siege by Jem'Hadar at a key communications outpost, AR-558, the largest Dominion communications array in the sector.
Dukat, now a religious leader of a Bajoran Pah-Wraith cult, holds Kira hostage. Mika, one of Dukat's followers, gives birth to a half-Cardassian child.
Nog struggles with PTSD from the traumatic battle of AR-558 where he lost his leg. So, he begins living with Vic Fontaine.
Ezri goes to New Sydney to find O'Brien and uncovers some disturbing family secrets. Miles goes in search of the widow of Liam Bilby, Morica Bilby, whom he befriended in an undercover operation.
Stardate: Unknown. The Grand Nagus goes missing in the mirror universe, leading Quark and Rom on a mission to track him down.
Ezri summons Joran, a homicidal Dax incarnation from her past, for help in understanding the mind of a serial killer loose on the station.
Stardate: 51474.2. A shapeshifter, one of "the hundred" sent from the Link centuries ago to explore the galaxy, tries to convince Odo to abandon his life as a humanoid in favor of a grander quest.
Stardate: Unknown. A surprise programming feature brings mobsters to take over Vic's lounge, leading the DS9 crew to devise a plan to get rid of them.
Stardate: Unknown. When the mysterious Sloan attempts to recruit Bashir for an undercover mission on Romulus, Sisko orders Bashir to go along with the plan, in hopes of learning more about Section 31.
Stardate: 52576.2. While Ezri goes searching for Worf, who has been missing since a Dominion attack on his ship, Sisko proposes marriage to Kasidy and begins plans to build a house on Bajor.
Captured by the Breen, Ezri and Worf undergo mental torture. Sisko agonizes over his broken engagement. Kai Winn receives her first vision; she learns a messenger will be sent to her. It is a simple Bajoran farmer, who is actually Gul Dukat in disguise.
An alliance is born between the Dominion and the Breen which will prove devastating for the Federation. Ezri and Worf are sentenced to death on Cardassia. Initially horrified, Kai Winn eventually accepts her visions are from the Pah Wraiths.
The war reaches a crucial turning point when the Dominion retakes the Chin'Toka system, the only Allied foothold in enemy space. Winn learns that Dukat plans to release the Pah-Wraiths. Damar begins a revolt against the Dominion.
Sisko orders Kira, Garak and Odo to Cardassia to assist Cardassians in resistance tactics as Damar's rebellion gains ground. Bashir makes a shocking discovery about the disease that is ravaging the Founders. Dukat's cover has been blown by Sobor. Gowron arrives on DS9.
Kira masterminds a plot to steal a Breen energy-dampening weapon. Gowron's political vendetta against Martok is endangering the war effort and prompts Worf to instigate a power shift in the Klingon Empire.
As Odo falls gravely ill to the shape-shifter disease, Bashir and O'Brien must get inside the mind of Luther Sloan, who holds Odo's cure.
Sisko takes command of a new ship. Kira, Damar, and Garak stumble into a Dominion ambush on Cardassia; they also discover the entire resistance organization has been destroyed. Ezri and Julian finally clear the air with each other. Grand Nagus Zek has an announcement to make, as does Kasidy Sisko.
Stardate: 52902.0. As the war careens toward a final showdown on Cardassia, Sisko's definitive action as the Emissary draws near.