Worf is in the Defiant. He wanders the halls, which are filled with dead Starfleet officers, and sees a squad of Klingon warriors raising their bat'leths in triumph. Worf then finds himself in front of the door leading to the bridge and he forces it open. Worf looks around and notices that the bridge is littered with many dead Klingon children. Worf wakes up with a scream to find that his vision was only a dream, and he is in a holding cell awaiting a hearing.
Admiral T'Lara convenes the hearing aboard Deep Space 9. Ch'Pok, the prosecutor and representative of the Klingon Empire, charges Worf with destroying a civilian transport ship and killing all 441 Klingons aboard. He requests that Worf be extradited to the Empire. Captain Sisko, Worf's defense advocate, explains that the Defiant was under attack by Klingon warships, when the transport suddenly decloaked in the midst of the battle, and that its destruction was an unavoidable accident.
Sisko meets with Odo in an attempt to find more exonerating evidence. Sisko's hunch is that the transport captain decloaked to attack the Defiant, so Odo's task is to find out everything he can about the crew of the transport. Odo leaves, and Ch'Pok approaches Sisko. Ch'Pok tells him that, if Worf is convicted of this massacre, the Klingon Empire will have a pretext to escalate its offensives against the Federation.
The hearing reconvenes. Ch'Pok accepts Worf's account of the situation, noting that, to Klingons, what matters is Worf's motivation, and whether duty or bloodlust informed his decision. T'Lara allows the hearing to move towards understanding Worf's motives, and Ch'Pok calls his first witness, Commander Jadzia Dax, to the stand. Dax serves as a cultural expert on the Klingons, largely due to the experiences of Dax's previous host Curzon Dax, and Ch'Pok tries to get her to define Klingons as a predatory, violent people. She defends Worf, noting that he is excellent at restraining his passions in the name of duty. Ch'Pok then enters into evidence a holosuite program, "The Battle of Tong Vey." The file was taken from Worf's database without a search order, but Worf allows it to be admitted out of his sense of honor. Dax summarizes the battle - in which Sompek conquered the city of Tong Vey with ten thousand warriors, then ordered the city burned and its people – men, women, and children – killed. Ch'Pok notes that Worf plays the role of Sompek in the holographic reenactment of it, and that he ran the holoprogram the day before the convoy mission, ending it with the order.
Ch'Pok examines Sisko, asking him why he chose Worf for the mission. The Cardassian colony on Pentath III was experiencing an outbreak of Rudellian plague, and Starfleet was sending medical aid. However, Pentath III bordered Klingon space, so the Defiant was sent to escort the medical convoy. Sisko explains that he wanted Worf to have more command experience, and, as a Klingon, he would be well-suited for an escort mission that might involve an altercation with Klingons. Next, Quark testifies about a brief conversation he had with Worf prior to the mission, in which Worf mentioned he "hoped" the Klingons went after the convoy. Worf is embarrassed - clearly, Quark told the truth.
Odo reports to Sisko that the transport captain was not at all the kind of person who would attack the Defiant. Sisko tells Odo to look into the background of each passenger on the transport ship.
Back at the hearing, Sisko calls Chief O'Brien. O'Brien explains the battle - in which a Klingon Bird-of-Prey and a battle cruiser would alternate attacking the Defiant and the convoy. The Klingon ships would fire, then cloak, then decloak and fire again. The Defiant was pursuing the Bird-of-Prey when it cloaked. They projected its course and followed it when O'Brien picked up a tachyon surge and Worf ordered Quantum Torpedoes fired at it. As the ship exploded, they realized it was simply a civilian transport. O'Brien reaffirms that he stands by Worf's decision and that Worf is an honorable man. Ch'Pok cross-examines O'Brien. He points out that O'Brien has served during 235 combat encounters and has been decorated by Starfleet fifteen times, and asks that he be declared an expert on starship combat. Ch'Pok asks O'Brien if he would have made the same decision had he been in command. O'Brien admits that he would not have, but that it reflects his opinion made now, weeks after the incident, not the heat of the moment.
In the Replimat, Sisko is drinking coffee when Ch'Pok takes a seat next to him. He offers to defend Worf himself if Sisko concedes now and allows him to be extradited. Sisko counters that Ch'Pok is still only after grounds to invade the Pentath system. Worf will testify next, and Ch'Pok tells Sisko that he should be worried. Sisko replies that Ch'Pok has revealed one thing--Ch'Pok is worried.
Odo informs Sisko that none of the passengers had any connection to Worf or Starfleet or any perceivable motive whatsoever, but that he will keep looking. In the hearing, Worf is testifying, explaining the mission. He says he was excited by the opportunity to do battle, and that although he respects O'Brien, he was not in a position to make such a command decision and he would have made the wrong choice. Worf tells Sisko that he knew there was a chance that he would run into a civilian ship, but it was a very remote chance, and that he was more concerned with the welfare of the convoy and his ship than such a slim possibility.
Ch'Pok cross-examines Worf. He begins by trying to establish that Worf is angry at the Empire because of his discommendation. Worf says he is hated by his people because of this, but Ch'Pok asserts that they hate him on a more basic level, because he is more human than Klingon. Ch'Pok establishes that Klingons are now his enemies, but Worf says he is not happy with killing civilians because there is no honor in it. Ch'Pok counters that a true Klingon relishes killing all of his enemies, armed or not, and would be happy for the dead children now in Sto-Vo-Kor, not grieved. Ch'Pok says Worf lives with humans out of fear of Klingons, to which Worf replies with a martial challenge. T'Lara threatens to hold both parties in contempt of court. Ch'Pok continues, arguing that Worf was eager for the Klingons to attack because he wanted to prove himself to other Klingons, and that one day Alexander will grow up to find out his father is a coward who killed innocent people to prove his own courage. At this, Worf gets up and attacks Ch'Pok with a series of blows. Sisko gets up to restrain him, as Ch'Pok closes his examination with the proof that Worf will attack an unarmed man if he is angry or has something to prove.
Sisko sits in his office, as Odo brings in a PADD. The hearing reconvenes and Sisko enters this new evidence, and asks Ch'Pok to testify as an expert on the Klingon Empire. Sisko hands Ch'Pok the PADD and asks him to identify the list of names. He answers that they are the victims of Worf's alleged attack. Sisko then explains that this list is actually of the victims of another crash that occurred three months before. Sisko asks Ch'Pok whether it would be possible that the transport was empty and was giving off false sensor images to justify an armed escalation, and Ch'Pok admits that it is. The trial is over.
Worf is in his quarters on the Defiant, lost in thought. Sisko comes in, and Worf admits that he should not have accepted the mission as he did have something to prove when he took command and, just like when Ch'Pok was goading him during the trial, he was hoping for an excuse to fight. He is prone to want vengeance, and he should not have fired on a decloaking ship regardless of the circumstances. Sisko agrees and sternly reminds him that he should have checked especially as he knew there were civilian ships in the area but instead fired on something he hadn't identified. Sisko lectures him on taking a command with such a predicament, and reaffirms that a Starfleet officer should never even take a chance of endangering civilians, even if it means the lives of the Starfleet officers will be lost. Nonetheless, Sisko says, there are no dead civilians on his conscience, and Worf will make a great captain one day. Sisko invites Worf to a party at Quark's, and Worf does not want to go, but Sisko reminds him that sometimes a command officer must sometimes smile even when it's the last thing they want to do in order to keep the troops happy. Worf muses that his life has become a lot more complicated since he started wearing the red uniform, but Sisko tells him it's nothing compared to when he gets four pips on his collar. The two then leave for Quark's.