Sisko's crew joins an exhausted Starfleet garrison holding a captured Dominion relay on AR-558 against a Jem'Hadar assault.
The Defiant delivers supplies to AR-558, where a Starfleet garrison holds a captured Dominion communications relay. Sisko, Bashir, Ezri, Nog and Quark, sent on a fact-finding trip, find the defenders in terrible shape: only 43 of 150 remain, they have gone five months without relief, and invisible Houdini mines that shift in and out of subspace kill without warning. Nog admires the hardened veterans, while Quark warns him how war strips people down.
When the Jem'Hadar move to retake the relay, Sisko sends the Defiant away and takes command. A scouting party gains vital intelligence, but its leader, Lieutenant Larkin, is killed and Nog loses a leg. Ezri and the engineer Kellin turn the Houdinis against the attackers, and the garrison holds at great cost, with Quark shooting a Jem'Hadar to protect Nog. The seventh-season episode is among the grimmest portrayals of the war and the price paid by ordinary soldiers.