Star Trek Neglected Worf's Brother Kurn, And We're Here To Fix That
In the "Star Trek: The Next Generation" episode "Sins of the Father," Worf (Michael Dorn) learned that he had a brother named Kurn (Tony Todd) who arrived on the Enterprise to recruit Worf for a special mission. It seems that their deceased father, Mogh, had been posthumously accused of treason by the Klingon High Council. Worf and Kurn needed to go back to the Klingon homeworld to make an appeal and clear their father's name; in Klingon society, the crimes of one generation implicate the next. Worf and Kurn, if they are unsuccessful, will be excommunicated from Klingon society — a grievous shame indeed — and executed in their father's staid.
At the end of the episode, it was revealed that Mogh had been framed ... by the father of Duras (Patrick Massett), a Klingon nobleman and heir to the throne. It seems that everyone knows how dirty Duras was, but to expose him would throw the Klingon homeworld into chaos. Worf, instead of fighting the system, chooses to take the heat for Duras' father's crimes, all for the good of the empire. Worf's life is spared and he is excommunicated. He will live out his days in shame. Kurn, meanwhile, was spared the shame of both fates, as he had been living under an assumed identity this whole time anyway.
With its Klingon episodes, "Star Trek: The Next Generation" became massively complicated, almost like a socio-political soap opera. Klingons had their own culture, and the show's Klingon stories were a vast network of supporting players and political intrigue that stood apart from the dealings of the Federation. Worf was the conduit into this world, so it was rare that the entire crew of the U.S.S. Enterprise became involved in Klingon stuff.
Kurn was a key player in these stories.
Kurn, the recruiter
Kurn only appeared in four episodes of "Star Trek," but had a massive tragedy all his own. In "Sins of the Father" and the two-part episode "Redemption," Kurn would appear to Worf to bring him back to the Klingon homeworld to address malfeasance thereupon. In "Redemption," Kurn became upset that the new Klingon emperor, Gowron (Robert O'Reilly), wouldn't use his executive power to pardon Mogh and reinstate Worf. Kurn was outraged that he had to live under an assumed name, aching to rejoin the Klingon empire with his birthright intact. When Worf refused to kill Gowron over this, Kurn became incensed. Indeed, Worf eventually ordered Kurn to support Gowron against Duras in an encroaching Klingon civil war. In so doing, Gowron restored the Mogh family name.
Yes, it's all very complicated, and it took two episodes to cover. I didn't even get into Lursa and B'Etor (Barbara March and Gwynyth Walsh), the Duras sisters. So that should be the end of it, right? Kurn, even though he didn't want to, defended Gowron against Duras, and was reinstated into the Klingon honor system as a result. That sounds like a happy ending.
It seems, however, that Worf's continued career in Starfleet cast a pall over Kurn's life, and his life slowly turned to crap after the events of "Redemption." Kurn's final appearance on "Star Trek" was in the "Deep Space Nine" episode "Sons of Mogh," a tragic episode wherein Kurn revealed the true dishonor he had been suffering ever since his last appearance. It seems that Worf, in serving with Starfleet and fighting against the Klingon empire on several occasions, was more or less considered an outright defector back on the Klingon homeworld. Just like with Mogh, that reflected poorly on Kurn.
Worf: bad brother
Worf, a bad family member all around, never even considered Kurn's fate. In "Sons of Mogh," Kurn explains that despite being exonerated, the House of Mogh lost all its graces with the Klingon High Council and was kicked out in shame. Gowron, embarrassed that Worf fought against him, stripped Kurn of all his property and left him honorless and destitute. Kurn arrived on Deep Space Nine to find his brother living in comfort with his new alien friends, never bearing in mind the consequences of his actions. Kurn had nothing. The only way to restore his honor, Kurn felt, was for Worf to stab him in a specialized ritual.
Worf, feeling it the decent thing to do, agrees to kill Kurn. Because his DS9 friends are savvy to Klingon rituals, however, the ritual is interrupted and Kurn's life is saved. This is the opposite of what he wanted. Kurn just wanted to die. He is horrified to be alive, but to make amends, he is offered a position as a security officer on the ship. If Kurn can't live honorably with Klingons, he can at least live in comfort with his brother. Kurn begins to join Worf on various Federation missions and sees that the politics of the Klingon Empire are dodgy at best. They're pulling out of certain accords and generally behaving dishonorably. Kurn is now torn.
Worf may be the one who is most often seen wrestling with his Klingon identity, but poor Kurn is the one who truly lost something. He lived as an outsider for years, having to lie about his family name, embarrassed that he was never permitted to be honest. All of Kurn's issues are through the actions of his family. Kurn only received fallout.
Kurn's fate
Worf, meanwhile, has lived away from the Klingon Empire for so long, he can no longer really return. His Klingon identity has become less and less important to him. Kurn, in doubting the Empire, is also now trapped between worlds. He would like to serve on a starship, but his habit of killing treason suspects isn't really the way the Federation operates. Neither likes their position. Kurn tries to behave like a Starfleet officer but simply doesn't have the wherewithal.
Kurn, finally realizing that he no longer has a place with Klingons or aliens once again asks for the murder ritual. Worf, also disconnected from the Klingon world, refuses this time. It seems that both are alienated from their culture. The difference between Worf and Kurn, however, is that the former did it deliberately. The latter only suffered as a direct result of Worf's actions.
Worf, as a solution, asks that surgery be performed on Kurn to alter his appearance. Dr. Bashir (Alexander Siddig) is also able to wipe out most of his memories, leaving him without an identity. This isn't much of a loss for Kurn who feels he lost his identity anyway. Kurn is taken in by a friend of his father, given a new name, and freed to form a new life from scratch. While leaving Deep Space Nine, Kurn passes by Worf. Do we know each other? No. Worf has no family.
Worf sucks as a brother. When it comes to caring for family, Worf knows only neglect. He is self-absorbed and preoccupied with ritual. Worf also famously neglected his son, never checked in on a paramour, and didn't correspond with old friends. He's an honorable dude, but he will not text you back.