Starfleet Command decides to take the offensive in the war against the Dominion, and Sisko is chosen to lead the invasion of Cardassia. The first target is the Chin'toka System, picked for its diminished defenses. Unfortunately, the crew is unaware that the Cardassian/Dominion Alliance has secretly deployed hundreds of orbital weapon platforms to protect system, and that Gul Dukat has returned claiming he has the key to destroying Sisko and the Federation.

Andrew J. Robinson (Garak)
Jeffrey Combs (Weyoun)
Marc Alaimo (Gul Dukat)
David Birney (Letant)
J.G. Hertzler (General Martok)
Aron Eisenberg (Ensign Nog)
Casey Biggs (Legate Damar)
Barry Jenner (Admiral William Ross)
James Darren (Vic Fontaine)

• Season Finale.
  
• Admiral Ross presents Sisko with the Christopher Pike Medal of Honor.
  
• When Worf and Dax decide to have a baby, Bashir gives Dax an ovarian treatment to make them genetically compatible.
  
• Damar has been promoted to Legate (Cardassian equivalent of Admiral).
  
• The Federation and Klingons unite with the Romulans to invade Cardassia. The Prophets warn The Sisko that he is of Bajor, and he must not leave. He ignores them.
  
• Dukat becomes possesed by a pah-wraith. (Pah-wraiths were also featured in "The Reckoning" and "The Assignment".) He beams into the Bajoran temple on DS9, fatally injures Dax, and then the pah-wraith exits him and destroys a Bajoran orb (and they all turn dark). The Wormhole opens and closes, and when it disappears, Sisko feels a disturbance in the Force.
  
• Jadzia dies, but Bashir saves the Dax Symbiont and sends it back to Trill.
  
• Sisko takes a leave of absence, and he returns to Earth with Jake. He takes his baseball with him....
  
• With this episode Terry Farrell officially leaves the cast.