The episode is one of three chosen for Paramount's "The Next Level" Blu-ray sampler. During the HD remastering process a 13-second portion of the episode had to be upconverted from a standard definition source as the original 35mm elements could not be located. This footage was later located and remastered in HD for the third season Blu-ray set.
As part of the Federation-Klingon officer exchange program, Klingon Commander Kurn has requested to be placed aboard the Enterprise as first officer. His typical Klingon-styled command style aggravates the crew, particularly Lieutenant Worf. Worf confronts Kurn alone, where Kurn reveals he is Worf's younger brother; when the rest of Worf's family left to the Khitomer colony, he was left with a friend of their father, Lorgh. Kurn was raised as Lorgh's child, unaware until recently of the massacre at Khitomer. Kurn tells Worf that their father Mogh is being charged posthumously as a traitor by Duras, the son of Mogh's rival, in the Khitomer massacre, which will mar the Mogh family name for generations. Worf requests an urgent leave of absence to defend his father's honor. Picard believes that Worf's actions as a Starfleet officer in his father's defense will be of significant interest to the Federation and directs the Enterprise to the Klingon homeworld so they may monitor the events. En route, Kurn volunteers to be Worf's Cha'DIch, a second to stand with Worf during the challenge. Worf agrees, but warns Kurn to not reveal his bloodline just yet.
At the High Council, Duras reveals evidence of Mogh sending Khitomer's defense codes to the Romulans. Worf challenges this, but is told privately by the aging K'mpec, the Klingon Chancellor, to drop the challenge and return to the Federation. Worf discusses this curious request with Picard, who also finds it strange and orders his crew to examine the evidence. Meanwhile, Duras has ambushed Kurn, aware of his Mogh bloodline, and attempts to get him to betray Worf. Kurn refuses and is seriously wounded, no longer able to support Worf in front of the Council. Picard, although not thrilled by the idea, accepts Worf's request to take Kurn's place.
The Enterprise crew finds evidence that the Khitomer logs have been modified and soon discover one more survivor of the massacre, Worf's nurse Kahlest. Picard is able to convince Kahlest, who knows Mogh was loyal to the Klingon Empire but does not know who the true traitor was, to help in Worf's challenge. Picard brings Kahlest to court and bluffs that she knows who the true traitor was, starting a heated dispute that is sure to end in needless bloodshed. Infuriated and as a means to halt the bickering, K'mpec calls Worf, Picard, and Kahlest into his private quarters and reveals the truth; the Council is well aware that Duras' father was the Khitomer traitor, but exposure of this, given Duras' high political position and capital, would certainly lead to an unwanted civil war within the already trouble-stricken Empire. The Council only accepted Duras' charge of treason against Mogh believing that Worf would not challenge it for this reason and this reason only. To prevent further upheaval, K'mpec imparts that the Council will condemn Worf and Kurn, but Picard refuses to let this blatant injustice stand, thus creating a situation that could end the Klingon-Federation alliance. Worf, seeing what restoring his family's honour may cost, steps in and says to understand what he needs to do, that the only course of action for Worf is to accept a discommendation, tantamount to admitting his father's guilt; in exchange, the knowledge of the proceedings, including Kurn's true bloodlines, will be disavowed. Back in the council, all of the assembled Klingons, including a reluctant Kurn, ceremoniously turn their back to Worf in his disgrace, and he and Picard silently leave the hall.