->''"Captain's Personal Log: Stardate 5-1-7... [unsure] 5-1-7... 4? Computer – what day is it?" "[COMPUTER VOICE] Stardate 51721.3." "It's only been two weeks... I need to talk about this. I have to justify what's happened... what I've done... at least to myself. I can't talk to anyone else... not even to Dax. Maybe if I just lay it all out in my log, it'll finally make sense... I can see where it all went wrong... where I went wrong... I suppose it started two weeks ago while I was posting the weekly casualty list in the wardroom... every Friday morning, for the past three months, I've posted the official list of Starfleet personnel killed, wounded or missing in the war. It's become something of a grim ritual around here. Not a week goes by that someone doesn't find the name of a loved one, a friend or an acquaintance on that damned list... I've grown to hate Fridays."''
-->'''-- Opening narration by Sisko'''

As the death toll mounts, Captain Sisko realizes that the only way to turn the tide of the war is to enlist the help of the Federation's oldest enemy: The Romulans. However, the Romulan Star Empire has declared neutrality. What reason could the Romulans possibly have to dirty their hands in the bloodiest war in the history of the Alpha Quadrant? Sisko's search for that reason forces him to cross one moral line after another.

This is perhaps one of the most controversial episodes of Star Trek ever produced. For some, it's one of the finest episodes in canon, showing how war is a very complex thing, and that sometimes, you must be willing to sacrifice your own morals for the sake of the greater good. For others, it's a complete slap in the face of Roddenberry's vision of the future, and an abandonment of the ideals that the Federation was built on. It's very polarizing, to say the least.

!Tropes in this episode:
* AndNowForSomethingCompletelyDifferent: The entire episode takes the form of a captain's log entry, with the audience taking the perspective of the computer.
* AntiHero: At the end of the episode, Sisko lists the numerous ways he's violated the law and his own integrity for the sake of the Federation.
* ArmorPiercingSlap
* AssholeVictim: Grathon Tolar. He was already slated for execution by the Klingons. While on the station, he attacked one of Quark's Dabo girls for refusing to "dance" with him (possibly [[AttemptedRape attempting sexual assault]], judging by the state of her clothes), and stabbed Quark for trying to defend her. Judging by how he behaved while on parole, the Klingons may have had very good reasons indeed to want him dead. Garak also may well have selected Tolar due to how expendable he was just as much as his considerable, yet "not quite up to the task" forging skills.
* BarBrawl: Off-screen, but recounted in detail by Odo.
* BatmanGambit: Sisko and Garak pull one on the Romulans.
* BigWhat: Sisko's reaction to the payment of bio-mimetic gel required for the data rod.
* BlackAndWhiteMorality: Very much {{Subverted}}.
* CallBack:
** One reason why Bashir is so reluctant to prepare the biomimetic gel is that [[Recap/StarTrekDeepSpaceNineS03E18DistantVoices Sisko is not the first person to demand some of it from him]] and it turned out not to be just a friendly request the last time either.
** Speaking of Bashir, in the [[Recap/StarTrekDeepSpaceNineS06E18Inquisition last episode]], while talking about [[NoSuchAgency Section 31]], he semi-rhetorically asks Sisko if TheFederation is willing to compromise its principles to survive, and all Sisko can say is, "I wish I had an answer for you." Well, now he has his answer...
** There's a subtle one combined with a bit of Fridge Logic: note that when Sisko first enlists Garak to help him get his hands on those top secret Dominion war plans to attack the Romulans, Garak never questions that some such plans exist, only that he or anyone he knows can possibly lay hands on them. That's because he's quite certain they exist. [[Recap/StarTrekDeepSpaceNineS05E14InPurgatorysShadow As the female changeling told him, the Dominion considered any race that dared attack the Founders as good as dead]]; and the Romulans were among its attackers!
* DarkerAndEdgier: Boy is it ever.
* DispenseWithThePleasantries: Sisko is in no mood for Garak's brand of loquaciousness.
* EndangeredSouffle: Sisko mentions this trope while quoting his father during one of his monologues:
--> "Worry and doubt are the greatest enemies of a great chef. The soufflé will either rise or it won't--there's not a damn thing you can do about it, so you might as well just sit back and wait and see what happens."
* ExpectingSomeoneTaller: Vreenak meeting Sisko:
--> '''Vreenak:''' So you're the commander of Deep Space Nine. And the Emissary of the Prophets. Decorated combat officer, widower, father, mentor and... oh, yes, the man who started the war with the Dominion. Somehow I thought you'd be taller.\\
'''Sisko:''' Sorry to disappoint you.\\
'''Vreenak:''' To be honest, my opinion of Starfleet officers is so low, you'd have to work very hard indeed to disappoint me.
* FalseFlagOperation: Sisko and Garak's plan is to get the Romulans to enter the war on the Federation's side by showing them a faked recording of the Dominion planning to launch a sneak attack on Romulus.
* {{Foreshadowing}}: Vreenak having a replicated Romulan drink, noting how while very good, he was still not fooled in that it's only an approximation and not the real thing. It foreshadows his reaction to the recording.
* GoodIsNotNice: Sisko, especially when the Federation is backed into a corner and his forger Tolar hasn't behaved himself very well on parole. At one point, he threatens to send Tolar back to the Klingons and [[ColdBloodedTorture "tell Gowron to take his time"]] while executing him.
** The point of the whole episode. Sisko does many evil things, and he will do them again, if he had to. The concluding monologue comes very close to HeelRealization.
* HowWeGotHere: Sisko starts out saying things have gone wrong, we find out how very wrong indeed during the course of the show.
* IDidWhatIHadToDo: A point Sisko makes in his log, and which momentarily causes him to lose his composure and start ranting.
-->'''Sisko:''' That was my first moment of real doubt, when I started to wonder if the whole thing was a mistake. So I went back to my office; and there was a new casualty list waiting for me... People are ''dying'' out there... ''every day''! Entire worlds are struggling for their freedom! And here I am still worrying about the finer points of morality! No! I... I had to keep my eye on the ball! Winning the war, stopping the bloodshed, ''those'' were the priorities! So I pushed on. And every time another doubt appeared before me, I just found another way to shove it aside.
* KansasCityShuffle: Elim Garak guessed the Romulan senator would realize the recording was a fake, and planted a bomb on the senator's ship ahead of time. After the senator departs from a meeting with the Dominion to return to Romulus to expose the con, Garak blows up the ship. So, when the recording is found in the wreckage, the imperfections in the forgery appear to be a result of the explosion. With a seemingly legitimate rod in one hand, and a dead senator coming from a meeting with the Dominion in the other, the Romulans promptly join the war against the Dominion, as Garak and Sisko wanted.
* KilledToUpholdTheMasquerade[=/=]YouHaveOutlivedYourUsefulness: In addition to blowing up Senator Vreenak and his bodyguards, Garak arranged for his forger to die as well, leaving himself and Sisko the only people who know the real story.
* LargeHam:
** Sisko at times during his personal log monologues. And it is ''glorious.''
** Vreenak as well. One need only see his "It's a Faaaake!" line.
* LeaningOnTheFourthWall: Sisko's monologue is spoken to the station computer, but most of the time he's staring directly at the camera.
* ListOfTransgressions: Sisko does this for himself. It's a short list as the trope goes, but some of them are real doozies for a Starfleet Officer.
-->'''Sisko:''' I lied; I cheated; I bribed men to cover the crimes of other men; I am an accessory to murder.
* MovingTheGoalposts: Even though Tolar does as he's told, Sisko refuses to let him go unless the program passes the test.
* NotSoAboveItAll: As so gleefully noted by Quark after Sisko bribes him to drop the charges against Tolar.
--> '''Quark:''' Thank you for restoring my faith in the 98th Rule of Acquisition: "EveryManHasHisPrice."
* OhCrap: The look on Sisko's face when Vreenak holds up the data rod and says, "It's a ''faaaake''!"
* SarcasmMode: Sisko's announcement of the Romulans' entry into the war, alluding to a BlackAndWhiteMorality that he knows for a fact does not exist:
-->'''Sisko:''' So this is a huge victory for the good guys!
* ScrewTheRulesImDoingWhatsRight: But that doesn't mean it feels very right.
* ShockingDefeatLegacy: Betazed falls to the Dominion, solidifying Sisko's resolve to see his plan to fruition.
* ShoutOut: The episode's title comes from the Joker's CatchPhrase in 1989's ''{{Film/Batman}}'': "Have you ever danced with the Devil in the pale moonlight?" As Garak's actor Andrew Robinson noted, the lesson Sisko learns from Garak in this episode, figuratively speaking, is "You can't go to bed with the Devil without having sex."
* ThatsAnOrder: Sisko gives Bashir's objections to preparing the biomimetic gel short shrift, and just to show Sisko understands what a terrible risk he's taking, he already has the order ready on a PADD when Bashir asks to see it in writing.
* ThatsWhatIWouldDo: Garak ruthlessly exploits this trope, pointing out to Sisko that the Romulans will surely believe the Dominion blew up Vreenak's shuttle to stop him from bringing them its secret plans to invade the Romulan Star Empire because they would have done the ''exact same thing'' to anyone on his way to expose Romulan duplicity toward an ally.
* TheNeedsOfTheMany: How Garak justifies killing Vreenak. In the end, Sisko is forced to accept it.
--> '''Garak:''' And if your conscience is bothering you, you should soothe it with the knowledge that you may have just saved the '''entire Alpha Quadrant''', and all it cost was the life of one Romulan senator, one criminal... and the self-respect of one Starfleet officer. I don't know about you, but I'd call ''that'' a bargain.
* ThisMeansWar: The Romulans declare war on the Dominion. They very nearly ended up at war with the Federation instead.
* UnspokenPlanGuarantee: Both aspects are played straight. The plan that Sisko and Garak discuss step-by-step backfires miserably, while the plan that Garak keeps secret from Sisko (and, by extension, the audience) works perfectly. The latter part is [[JustifiedTrope Justified]] as Garak knew that Sisko would've never gone along with it.
* {{Unobtanium}}:
** The genuine Cardassian optolythic data rod Sisko and Garak require for their scheme is usually only manufactured by the Cardassian government on an as-needed basis. Obtaining it anywhere else requires "a small miracle".
** The highly-controlled bio-mimetic gel they end up having to trade for the rod can be used for illegal genetic experiments and building biogenic weapons of mass destruction. It is therefore not legally available at ''any'' price.
* WhamLine:
--> "Computer, [[ShaggyDogStory erase that entire personal log]]."
* WhatTheHellHero: Sisko punches Garak after he realizes the Cardassian planted a bomb in Senator Vreenak's shuttle. Garak immediately calls him out on his hypocrisy.
* WhatYouAreInTheDark: Sisko's delivery makes it clear that his real reason for recording the log entry is to convince ''himself'' that his actions were justified.
-->'''Sisko:''' But the most damning thing of all is... I think I can live with it. And if I'd have to do it all over again... I would.
** It's not at all clear that he succeeds.
-->'''Sisko:''' So I will learn to live with it. Because I ''can'' live with it. I '''can''' live with it... Computer, erase that entire personal log.
* WonTheWarLostThePeace: One of the ways Sisko tries to appeal to Vreenak, by pointing out that if the Dominion wins and ends up controlling the Cardassian Union, the Federation, and the Klingon Empire, then the Romulans will find themselves facing the same opponent on each side. The term for that? "Surrounded."