Sins of the Father

Commander Kurn joins the Enterprise under an officer exchange programme, and soon reveals that he is Worf's younger brother. He was left behind with a family friend when their parents went to Khitomer, where they died in a Romulan massacre. Now Duras, a powerful rival, has accused their father, Mogh, of giving Khitomer's defence codes to the Romulans. Worf goes to the Klingon homeworld to challenge the charge before the High Council, with Kurn as his second. When Duras's men ambush and wound Kurn, Picard takes his place at Worf's side. The Enterprise discovers that the Khitomer records have been tampered with, and finds Kahlest, Worf's old nurse and a survivor of the massacre. Chancellor K'mpec privately admits the truth: Duras's own father was the traitor, but exposing it could plunge the Empire into civil war. To keep the peace and protect Kurn's secret, Worf accepts discommendation. As he leaves the Great Hall an outcast, even Kurn turns his back.