The Defiant is about to go on a supply run to planet AR-558, the site of a Dominion communications relay that Starfleet captured. Bashir picks up some music from Vic Fontaine to deliver, while Sisko stews over the latest casualty reports before getting notified that the Defiant is ready. Onboard, Quark has joined the mission on orders from Grand Nagus Zek to get a Ferengi perspective on the war. As he vents to Ezri about his predicament, the ship comes under fire, and Quark rushes to the bridge to witness the ship destroy a Jem'Hadar fighter. Sisko leaves Worf in command as he beams to the surface with his away team.
Sisko and company come under immediate fire, but it turns out to be the Starfleet officers there to meet them. After five months on the front lines, they've become jumpy and exhausted. With their captain and commander dead, Lieutenant Larkin is in command. She tells Sisko that they are down to one-third strength and long overdue to be rotated out, but Sisko says they should expect to be there a while longer. His team sets to resupplying the defenders. Bashir treats the shell-shocked grunt Vargas, while the battle-hardened Reese dismisses Sisko's help given that he's set to leave soon. But when the Defiant comes under attack and needs to flee, Sisko decides not to beam away and instead stay to fight alongside the garrison.
The crew split up to help out. Ezri works with Crewman Kellin on finding a way to locate the invisible Dominion mines called "Houdinis" that have been killing off the Federation defenders. Quark is alarmed to find that Nog idolizes the defenders, particularly Reese, as heroes. Quark gripes that the Ferengi way would have been to negotiate a mutually acceptable treaty rather than fight. His fears for his nephew's safety get borne out when Nog gets shot in the leg on a scouting trip. Bashir operates, but Nog loses his leg, and he might not be a candidate for a prosthesis. Nog keeps on a brave face, however, assuring his uncle that he's fine. Quark confronts Sisko for using his men as cannon fodder, but Sisko angrily insists that he does care about his men.
Ezri and Kellin manage to decloak the Houdinis, and Sisko decides that they will relocate them to a chokepoint between the two bases to kill Jem'Hadar when they come to attack. The defenders buckle down to prepare for an invasion, and everyone is on edge. Bashir plays the Vic Fontaine music to ease the men's nerves. Quark stays with Nog in the infirmary. The defenders hear explosions and screams as the Jem'Hadar stumble into their trap and reveal their impending attack.
The surviving Jem'Hadar rush into view, and Sisko orders everyone to open fire. It's a huge phaser fight. The Jem'Hadar break through the Federation barricade and engage in brutal close-quarter combat. Vargas goes down with a knife in the back. Kellin saves Ezri's life and then gets killed himself. Bashir gets hit. Sisko and Reese both fight off Jem'Hadar soldiers and help push them back. In the infirmary, Quark hears someone approaching and beats a Jem'Hadar on the draw, saving his and Nog's lives. Sisko gets knocked out, and when he awakens, Reese announces that the day is won.
Reinforcements finally arrive to take the defenders' places. Reese describes the green troops as "kids," but Sisko says that they will grow up fast. Back on the station, Sisko receives the latest casualty list of 1,730 names. He grimly tells Kira that every name is a person, and it's important to remember their sacrifice.
This episode contains examples of:
- An Arm and a Leg: Nog loses a leg during a Jem'Hadar ambush.
- Battle Trophy: Reese keeps a necklace of Ketracel-White tubes hung around his neck. Episode writer Ira Steven Behr called this "about as grisly as we could get on Star Trek."
- Bittersweet Ending: Starfleet succeeds in holding the communications array, but almost everyone from the Federation garrison has been killed, and Nog has lost his leg.
- Break the Cutie: Nog gets shot, and his leg is amputated.
- Call-Back: The Starfleet and Dominion forces jam each other's sensors, just like the Klingons did in "Nor the Battle to the Strong".
- Casting Gag: Kellin, the engineer at AR-558, is played by Bill Mumy, who played Will Robinson on Lost in Space, one of Star Trek: The Original Series's Dueling Shows, and Lennier in Babylon 5, one of DS9's Dueling Shows. One of his conditions for appearing in the episode is that he insisted on playing a human, so he wouldn't have to wear heavy prosthetics like he did for his entire run on Babylon 5. In the reunion documentary, producer Ira Steven Behr revealed that he made it a point to visit the set for Kellin's death scene because he was eager to see "Will Robinson" get shot.
- Chekhov's Gun: Vic Fontaine records a few songs for Bashir to take to the front lines. He then plays one of them ("I'll Be Seeing You") just before the climactic battle.
- Closest Thing We Got: Ezri has to assist in the engineering work because Tobin, one of the past Dax hosts, was an engineer; her knowledge from Tobin is obviously behind the times, but it's still better than what most of the officers available here are capable of.
- Combat Medic: Bashir expertly field-strips, cleans and reassembles a phaser rifle (impressing Vargas), commenting on the irony of his having "joined Starfleet to save lives." He acquits himself well in the battle.
- Conditioned to Accept Horror: Reese.
- Darker and Edgier: One of the darkest episodes of the whole franchise, providing a wholesale Deconstruction of Roddenberry's vision of an ideal future humanity.
- The Dead Have Names: Sisko and Kira both state this at the end. And subverted, in that Sisko says that's not enough.Sisko: They're not just names, it's important we remember that. We have to remember.
- Due to the Dead:
- Sisko still reads the lists of those killed in the war.
- Vargas at first refuses to allow Bashir to touch the bandage that was given to him as the last act of a comrade. He admits that he actually hated the Know-Nothing Know-It-All but still feels indebted to him.Vargas: McGreevey put this bandage on me. He ripped up his own uniform to make it.
Bashir: He sounds like a good friend.
Vargas: He was a jerk. I couldn't stand the guy. He wouldn't shut up. Yap, yap, yap, yap. He thought he was the world's greatest authority on everything. I know, he's dead and I should have more respect, but God I hated him. One moment he's tying the bandage around my arm, talking his head off, and the next minute he's lying flat on his back with a hole in his chest. And I just sat there and I looked at him. That was so great. He was so quiet. One time in his life he's quiet!
- Fantasy Conflict Counterpart: In keeping with the Dominion War being analogous to World War II, this episode was directly based on the Battle of Guadalcanal. Just swap Henderson Field for the communications array. Director Winrich Kolbe additionally drew on his experiences in the Vietnam War, feeling it was similar to Khe Sanh.
- A Father to His Men: Sisko, and he makes damned sure Quark understands that.Sisko: Listen to me, Quark, because I'm only going to say this once... I care about Nog and every other soldier under my command. Understood? Every damn one of them.
- Gallows Humor: The Federation soldiers nickname the Dominion's phasing mines "Houdinis". Find one, and you disappear.
- Hoist by Their Own Petard: The Starfleeters use the Jem'Hadar's "Houdini" mines against them.
- Hold the Line: Sisko's order to the remaining troops. After the battle is over,Sisko: We held.
Reese: Those were our orders, sir.
- Hollywood Tactics: Other than the mines, neither side brings any weapons more powerful than rifles. The Federation doesn't emplace anything heavier to cover the single line of approach beyond re-purposing the Dominion's own mines. No one even uses infantry-level heavy weapons. Some of this is justified in that the Federation side is ill-equipped, and the Dominion wants to preserve the communications relay. However, it's par for the course in the way Star Trek portrays infantry combat.
- Humans Are Warriors: An uncommonly negative example. Quark explains to Nog what Hew-mons are like:"Let me tell you something about Hew-mons, nephew. They're a wonderful, friendly people - as long as their bellies are full and their holosuites are working. But take away their creature comforts... deprive them of food, sleep, sonic showers... put their lives in jeopardy over an extended period of time... and those same friendly, intelligent, wonderful people will become as nasty and as violent as the most bloodthirsty Klingon. You don't believe me? Look at those faces, look at their eyes..."
- I'm a Doctor, Not a Placeholder: Kellin is an engineer, not a magician.
- In the Back: Vargas is stabbed in the back during the final battle.
- Jerkass Has a Point: Quark spends the episode insulting the Federation defenders, but he's not terribly wrong about human nature in general, and he's shown to be justifiably concerned about Nog's idealistic attitude toward heroism.
- Manly Tears: Vargas sheds them when he tells the story of his comrade, who died bandaging his arm.
- Mauve Shirt: Four troops at AR-558 are given names and some characterization, the weary but professional Larkin, grim and battle-hardened Reese, shell-shocked Vargas, and Nice Guy engineer Kellin. Only Reese survives.
- New Meat: The relief troops at the end. Getting one look at them, Reese calls them "children."
- Offscreen Moment of Awesome: Ultimately, the battle is finished off screen after Sisko is knocked out.
- Papa Wolf: Although he hates war, Quark is quick to defend himself and his nephew from an attacking Jem'Hadar, beating the soldier to the draw and blasting him with one shot.
- Paranoia Fuel: The invisible floating mines are a disturbing In-Universe example. You can walk through the same place a hundred times, never knowing when a Houdini will emerge and give you the Red Shirt treatment.
- Pet the Dog: After bringing a wounded Nog back to base, Reese takes a moment to tell Sisko, "The kid did alright."
- Red Shirt Army: The garrison at the beacon site. Of four named troops, only Reese survives.
- Sci-Fi Writers Have No Sense of Scale: Given that the Dominion war involves a full-scale conflict between numerous nations numbering billions of citizens each, a weekly casualty report of 1,730 would be amazingly small.
- Shell-Shocked Veteran: Everyone at AR-558 - they were supposed to be rotated out after 90 days. They've been there five months with no relief and under constant attack to the point they went from 150 troops to just 43 by the time the Defiant shows up.
- The battle plays out much like the film Zulu. There's even a scene where Jem'Hadar are expended merely to test the defenses of the camp (of course, these Jem'Hadar were holograms).
- All of the soldiers stationed on AR-558 were named after characters or actors from the WWII movie Hell Is For Heroes.
- Soldiers at the Rear: Both engineers, Nog and the poor guy assigned to keep AR558 running.
- Soundtrack Dissonance:
- That's an Order!: Sisko orders Worf to break out of orbit when the Defiant is attacked, even though it means leaving the away team on the planet.
- Tragic Keepsake: Vargas's bandage, made from the uniform of a dead comrade.
- War Is Hell: This episode shows no glory, no love of battle. Just the harshness and a piece of rock which no one would care about if not for the technology put there. Just to emphasize the point, the released death toll at the end reminds everyone that this was one (relatively light) battle.
- Was It Really Worth It?: Sisko is having dark thoughts at the end of the episode, after the line has been held. Worf tries to cheer him up.Worf: This was a great victory. One worthy of story and song.
Sisko: It cost enough.
- Why Isn't It Attacking?: The Jem'Hadar who show up midway through the episode don't fire. They turn out to be holograms.
- Writer on Board: The director of the episode had fought in the Vietnam War and allowed his own experiences as a soldier to color the atmosphere of the scenes and really brought out the War Is Hell trope to the forefront, far moreso than was typical for Trek.
- You Are in Command Now: Lt. Larkin was left in command at AR-558 after Captain Loomis and Commander Parker were killed prior to Sisko's arrival. He takes command as the senior officer when the Defiant is forced to retreat.
- Zerg Rush: The Jem'Hadar try to overwhelm the Federation garrison with sheer numbers - literally stumbling over their own dead until they can close to melee combat range.