DS9 Season 2 Episode 3 The Siege

Plot

Bajoran assault vessels approach Deep Space Nine as part of a military coup against the Bajoran government led by the xenophobic "Circle" movement. Sisko announces that he is evacuating the station's civilian population and anyone who wishes to leave; the entire crew volunteers to stay with him and fight. Li Nalas calms the flood of civilian passengers by inspiring courage in his fellow Bajorans. Quark ends up left on the station when a scheme to make money buying and selling seats on the evacuation ships backfires.
Once the Bajoran forces arrive, there is no sign of Federation presence; however, General Krim suspects Federation personnel are still aboard. Coup leader Jaro Essa orders Krim to capture Li Nalas alive, convinced that he can bribe Li into joining the Circle. Krim's soldiers begin a search of the station; security chief Odo uses his shape-shifting abilities to help the crew avoid detection.
Kira and Dax are sent to bring evidence that the Cardassians are backing the Circle to Bajor. Dropped off on a moon where the Bajorans stored a number of small starfighters during the occupation, they manage to get one of the craft working and fly to Bajor. Their ship is shot down by Bajoran fighters and they crash.
Sisko and the crew trap a group led by Krim's second-in-command, Colonel Day, in a holosuite. Sisko informs the soldiers about Cardassian involvement with the Circle and releases Day to pass the information to Krim, but the colonel instead tells Krim that the Federation is attempting to wrest control of DS9 from the Bajorans. A scan for Federation communicator signals reveals that they are hiding in the conduits, and Odo informs Sisko that the soldiers intend to flood the conduits with gas. Part of the crew distracts the bulk of the Bajoran forces, after which Li and Sisko capture Krim in an attempt to reason with him.
Although Kira was injured in the crash, Dax gets her to Vedek Bareil's monastery. She and Kira disguise themselves as clerics to travel to the Chamber of Ministers. Once there, Kira confronts the ministers with proof of Cardassian involvement. Upon learning of the Cardassian involvement, Krim gives control of DS9 back to Sisko and goes down to Bajor to resign. However, Colonel Day attempts to assassinate Sisko in revenge; Li Nalas steps in the way of Day's weapon blast and is killed; Day is put under arrest. Later, Sisko tells Chief O'Brien that Li was a hero of the resistance and that is the way he will remember him.