In this episode of "O'Brien Must Suffer", it's time for O'Brien to go on vacation for the first time in five years. As he and Keiko take a runabout to their vacation destination, they are intercepted by a Cardassian patrol, they board and O'Brien is arrested and taken captive. O'Brien wakes up on Cardassia Prime where, after the Cardassian version of a mugshot and being offered the chance to confess to his crime, he is told his trial will be in two days. Through all of this, none of the Cardassians have told him what he has been accused of.
Back on Deep Space Nine, Sisko informs Keiko that several Federation ships have been deployed to the demilitarized zone to pressure Cardassia over O'Brien's capture. They are contacted by Makbar, the Archon who will be overseeing O'Brien's trial. She explains that O'Brien's charges will be announced at the start of the trial, as is customary in Cardassian jurisprudence, and in the meantime there is no need to prepare — his guilt has already been decided, the trial is to explain how and decide how severe his guilt is. As his spouse, Keiko has the right to attend the trial, and she will be accompanied by Odo, who, having been made an officer of the court during the Occupation, has requested to be O'Brien's advisor in the trial.
O'Brien meets his "defense attorney", Conservator Kovat. He explains that O'Brien's trial and sentence helps reinforce order and peace on Cardassia, the people will see a guilty man be caught and punished and they will feel safe in knowing a criminal has faced justice. Kovat's role is to try and coax a confession from O'Brien, not to prove his innocence.
On DS9, Sisko and Kira find two dozen photon torpedoes missing from weapons storage — the voice print to access it is O'Brien's, and it is possible a transporter could have swapped the crates without the security scanners noticing. Weeks ago a Maquis ship stole a supply of photon launchers, leading them to wonder if O'Brien's vacation was a cover to sell the torpedoes to the Maquis. Sisko begins an investigation into if the Maquis were behind the theft, while also raising the question of how the Cardassians could have suspected O'Brien was smuggling weapons. Dax analyzes O'Brien's voice print and realizes it was reconstructed by someone who had recorded O'Brien's voice.
Odo meets with O'Brien and explains the situation to him, but O'Brien maintains his innocence. The trial begins and Odo tries to present the evidence that O'Brien was framed, but Makbar shuts him effort down — the verdict has already been reached and no new evidence can be submitted now, and Makbar has no interest in whatever "evidence" the Federation may produce to prove O'Brien's "innocence".
The crew question Raymond Boone, a suspected member of the Maquis and former friend of O'Brien, who was seen talking to him as he left the station. He claims to know nothing. In medical, the lights go off and Bashir is confronted by an unknown member of the Maquis, who claims Boone is not one of them. Sisko and Bashir confront Boone and bring up many ways in which he began to act strangely eight years ago when he was released from a Cardassian detention center. They restrain him and Bashir conducts a medical examination. As O'Brien's trial winds down and Makbar prepares to sentence him, Sisko enters with Boone. Seeing them, Makbar decides there is room for compassion in Cardassia's courts, and O'Brien's verdict is set aside and he is released.
Back on DS9, the crew explain that Boone was a Cardassian, identified as such by the fact all Cardassians have a tooth extracted for purposes of identification at age ten. The real Boone apparently died in captivity, and a Cardassian was surgically altered to look like Boone to infiltrate the Federation. They believe this plot was to try and make it seem as though the Maquis were secretly being supplied by the Federation, so the Cardassians would have cause to pressure the Federation to leave the demilitarized zone and disband their colonies. With the plot exposed, O'Brien and Keiko can go on their vacation properly this time, Sisko having pulled strings to get them an extension.
- Abusive Parents: Kovat attempts to invoke this when trying to find "the underlying flaw" that would make O'Brien commit the theft. He asks him if his childhood was unhappy and abusive. O'Brien, naturally, is completely appalled at such a question and declares that he loved his parents.
- Affably Evil: Kovat is a kindly, grandfatherly gentleman who genuinely seems to want what's best for his client... "what's best" being that his client gets a swift guilty verdict to prop up the myth of the infallible Cardassian state.
- Affectionate Pickpocket: A variant - "Boone" bumps into O'Brien and then pretends not to recognize him so that Miles will identify himself, so the fake Boone can get a voice sample to open the weapons locker.
- Blackmail: How Sisko gets O'Brien released. He captures the Cardassian agent that engineered the theft of photon torpedoes that led to O'Brien's arrest. Sisko merely shows up in the courtroom with the agent, and the judge suddenly decides to release O'Brien (though still declaring him guilty) "in the interest of Federation/Cardassian relations". Sisko doesn't even need to speak a word.
- Black Comedy: A lot of the humor in the episode comes from the Cardassians' Kangaroo Court system running on Insane Troll Logic, but the consequences O'Brien faces are very serious.
- Blue-and-Orange Morality: Kovat and O'Brien clash continually because of the major differences between the Federation and Cardassian justice systems, and the corresponding mindsets that come with each—in Cardassia, even an innocent wrongly put on trial would know what to expect (and would eventually capitulate), but O'Brien, raised in a society where "innocent until proven guilty" is the norm, cannot accept the fate that he seems to be heading toward, and is intent on fighting even if he can't win.
- Butt-Monkey: O'Brien can't even go on vacation without becoming one.
- The way O'Brien initially gets treated by the Cardassians (forcibly stripping off his clothes, then shining bright lights into his face) bears resemblance to the Cardassians torturing Picard in the TNG episode Chain of Command.
- O'Brien's experience in the Cardassian justice system matches how Dukat described it.
- Chekhov's Gun: All Cardassians have their first molar extracted at the age of 10 for identification purposes.
- Chewbacca Defense: Odo's attempts to prove O'Brien's innocence are doomed from the start (and, under Cardassian law, are actually irrelevant), but his antics at least keep the trial going for much longer than intended (the judge laments it's already become the longest trial in the history of Cardassia), creating enough delay for Sisko to come in and save the day with incriminating evidence that would be embarrassing to the Cardassian State.
- Domestic Abuse: After failing to play the abusive parents card, Kovat tries to suggest that Keiko is abusive to O'Brien. He's offended by this and says that his wife is the most caring person in the world, to which Kovat throws up his hands and says "I tried."
- Frame-Up: O'Brien is set up as smuggling weapons to the Maquis, in order to give the Cardassians justification to enter the DMZ and attack them.
- Faux Affably Evil: Throughout the episode, Makbar acts like a Reasonable Authority Figure, even by Cardassian standards. Then it turns out she's part of the frame job done on O'Brien.
- Get Out!: Played for Laughs with Sisko and Kira telling O'Brien to please go on vacation already.
- Good Cop/Bad Cop: The "public conservator" is more of a Good Cop than a defense attorney, while the Arbiter acts more like a Bad Cop.
- Hero of Another Story: The Enterprise is this for once, as TNG had already ended. They're deployed near the DMZ after O'Brien is arrested, as a show of Federation resolve.
- Kangaroo Court: The inane and insane Cardassian "legal" system in on full display here. Kovat all but admits that the entire justice system is a farce to make the people feel safe and secure by seeing criminals punished, regardless of their guilt. To go over some of the absurdities on display:
- Exhibit A: O'Brien's Conservator (defense attorney) is more interested in getting him to confess and trying to provide sympathetic reasons for his actions to get the court to be merciful in the sentencing, which would mean O'Brien's death sentence would be quick and painless. The Archon takes the role of both prosecutor and judge.
- Exhibit B: O'Brien is arrested, processed, and held for days before ever being told what his crimes is. By the time he enters the courtroom and the trial formally begins, the verdict and sentence have already been decided.
- Exhibit C: Odo claims he has evidence that O'Brien is innocent. Kovat informs him that no evidence can be submitted after the verdict has been decided, which it was before the trial even started. Ergo, all the evidence was submitted, reviewed, and a verdict gleaned from it, all before the trial even began.
- Exhibit D: Odo points out no crime was committed against Cardassia, the crime O'Brien is accused of was commited aboard a Bajoran space station and within the demilitarized zone. Rightfully, any trial O'Brien is subject to should be under Federation jurisdiction. Makbar flat ignores this point.
- Exhibit E: Gul Evek claims that "reliable sources" told him O'Brien had the warheads and he was delivering them to the Maquis. When Odo questions who these "reliable sources" are, Evek says revealing his sources would compromise national security — the archon says this is acceptable and his testimony is permitted.
- Kill and Replace: The fate of the real Raymond Boone. Eight years ago.
- I Never Said It Was Poison: A major flaw in the plans of the Cardassians is that they arrested O'Brien for allegedly transporting weapons through the demilitarized zone, but there's no reason they would have suspected him of doing so, which means they knew he wasn't and it was a set-up.
- Large Ham: Conservator Kovat. He's more of a theater actor than a lawyer.
- Moment Killer: Nothing like being arrested by the Cardassians to assassinate a romantic moment between O'Brien and Keiko.
- Mysterious Informant: Bashir is told by an unknown Maquis agent that Boone is not one of them.
- Not Himself: "Boone" suddenly went from being a model Starfleet officer to a malcontent who was discharged for poor performance. He also left his wife, but she assumed the changes in his personality were due to being tortured by the Cardassians.
- Oh, Crap!:
- The archon's reaction when Sisko shows up with the fake Boone.
- When Kovat realizes he's actually won a case.
- Retirony: Kovat tells Odo that he's only a year to retirement, so he doesn't want this trial screwed up. After he in fact wins, Kovat fearfully says "They'll kill me..."
- Reverse Whodunnit: Boone is shown with a recording of O'Brien's voice in The Teaser, so when it's revealed that photon warheads were stolen from DS9 with O'Brien's voice authorization, it's obvious who was responsible. However, The Reveal that Boone is a Cardassian spy doesn't come until later, and the real question is whether or not this will have any effect on a Cardassian tribunal that's dead-set on convicting O'Brien no matter what.
- Series Continuity Error: While the exact date of the Setlik III Massacre was never firmly established, this sets it in 2362. Previous comments placed it in the late 2340s.
- Spot the Imposter: All the evidence against Boone is circumstantial, until it's revealed he's missing one of his molars.
- Springtime for Hitler: Kovat's job never was it to win the case for O'Brien. He then gets quite distraught when he actually does.
- Kovat and O'Brien actually don't "win" the trial. O'Brien is declared guilty, but has the death sentence commuted and he is released (with the excuse being that it's in the interest of Federation/Cardassian relations).
- Stereotype Reaction Gag: The Cardassians use O'Brien's Fantastic Racism as evidence against him, particularly his attitude that "the bloody Cardies can't be trusted". And then it's revealed that he's the victim of a Cardassian-engineered Frame-Up, which kinda proves him right.
- Think of the Children!:
- In the establishing shot of the Cardassian capital, there is a propaganda message on the viewscreens telling the people to "look to the children, invest in their minds."
- Kovat says those four words at the beginning of one of his speeches.