

TNG's Reunion is the third part in Worf's continued storyline where it combines two seemingly separate episodes by following up on both. One part featuring the return of K'Ehleyr from "The Emmisary" and the other part being the story that continues the events from "Sins of the Father". On one hand, we have to deal with the usual "Klingon Honor" schtick that is continuing to plague the Klingons of TNG. On the other hand, Yay! K'Ehleyr is back and she delivers the best response to this whole situation.
K'Ehleyr: The Klingon Empire is at a critical juncture. We may be facing civil war.
Riker: War over what?
K'Ehleyr: The usual excuses. Tradition, duty, honour.
It's so good to have her back, but unfortunately her return has come with a price. A price that I'm sad to say was totally not worth paying. She brought Worf's illegitimate son!

Moving on, "Reunion" is also the first episode of TNG to introduce Star Trek to one of it's most memorable reoccurring Klingon characters, Gowron! Not only will he play an important roll in Worf's continuing story in TNG, but will play a much larger one in the later seasons of Deep Space Nine. Robert O'Reilly plays the role of Gowron with such energy and commanding presence that it's impossible not to be intimidated by him. And that stare...

After a bunch of nonsense about who should rule the Empire and who follows the real way of the Klingons, K'Ehleyr decides to investigate into what actually happened with Worf during his discommendation, and Picard thinks she should mind her own gawddang business. So, in-universe we now have Picard to thank for what is about to come.
She soon snoops around some Klingon files and discovers the truth about Duras in his role on selling out the Klingons to the Romulans. When Duras comes into her quarters and confronts her about this, she makes the dumb decision by telling him that she knows everything. So off screen he proceeds to beat her to death, but not before both Alexander and Worf come to have one more family moment. Man, for medical emergencies, they really are slow. And poor Beverly. She's the ship's number one physician and even here she gives one tricorder reading and shakes her head.
So Worf, ticked off beyond known decides to go onboard the Klingon vessel and kill Duras. Riker tries to stop Worf from delivering the final blow, but Worf pays no attention and finishes Duras off. Back on the Enterprise, Worf gets lectured at by Picard, has a reprimand put on his record and is sent back to duty. Picard asks now that Duras is dead if he should finally come out with the truth about his family's innocence. Worf says it isn't time yet and the episode ends with a father and son bonding moment.
CONCLUSION:
A good continuation of Worf's story that started in with Season 2, but there's one element that still ticks me off to this day and I think everyone knows what that is. K'Ehleyr's death plays the "Women in refrigerators" trope the absolute "T". Her death is solely meant to motivate the male character into action and it's used even further to give us another father/son bonding moment, because we haven't had enough of that in this one season alone, haven't we?
STINGER:
Picard: mev yap! Sit down. We will begin the ja'chuq.
Gowron: What???