DS9 Season 7 Episode 8 The Siege of AR-558

Plot

The USS Defiant, commanded by Captain Benjamin Sisko, is dispatched to bring supplies to Starfleet soldiers on planet AR-558, the site of a captured Dominion communications relay. The Ferengi civilian bartender Quark accompanies them, having been sent on a "fact-finding mission" to the front lines.
Sisko, Quark, Dr. Julian Bashir, counselor Ezri Dax, and Quark's nephew Ensign Nog find the Starfleet garrison in bad shape: of 150 soldiers sent to the planet, only 43 still live; the captain and first officer have been killed, leaving Lt. Nadia Larkin in command. The remaining soldiers are badly in need of relief: they have not been rotated off-duty for over five months, although regulations insist that infantry be rested every 90 days. They are plagued by "Houdini" anti-personnel mines that pass in and out of subspace at random and kill soldiers unexpectedly. Although Nog looks up to the battle-hardened veterans as heroes, Quark warns him that humans deprived of their creature comforts can be brutal.
When the Dominion's soldiers, the Jem'Hadar, arrive to attempt to retake the installation, Sisko takes command of the garrison, ordering the Defiant away to safety. Over Quark's objections, Sisko sends Nog as part of a scouting party to assess the Jem'Hadar's strength. The party gains the needed intelligence but is ambushed; Larkin is killed, and Nog loses a leg. Quark accuses Sisko of not valuing Nog's life; Sisko retorts that he cares about all the soldiers under his command.
Dax assists the garrison's engineer, Kellin, in working out a way to make the "Houdinis" visible, so that they can be moved out of the camp and used to halt attacking Jem'Hadar. As the Jem'Hadar begin advancing, the Houdinis begin to explode in the distance. The Starfleet personnel prepare for the upcoming fight, while Quark waits with Nog in the infirmary. In the ensuing battle, the Jem'Hadar break through the Starfleet defensive lines; Quark shoots a Jem'Hadar soldier in the infirmary, protecting Nog. Although many Starfleet personnel are killed in the battle, they succeed in holding the installation.
In the aftermath of the battle, the Defiant returns, accompanied by the USS Veracruz, which evacuates the wounded and replaces them with fresh troops. Sisko reflects on the cost of the victory and the importance of remembering the dead as people, not just names on a list.