After their arrival, the dragonborn, bard and druid were tasked to go get the owlbears. Before leaving, they mentioned the hellhounds and gricks to Clease. Clease appeared concerned and warned them about the Night Hag.
Night Hags are evil, fey spirits that inhabit corrupted Elven women. They are nature spirits that have taken over the Elven body. The Elf's mind is still locked in there, constantly being tortured, but can exert some control over the creature. This moral compass is what causes the Night Hags to enter into deals and compacts with other creatures, and when wronged, the Night Hags lash out with terrible vengeance.
While taking the party part way to the owlbears, Clease explained that he had made a deal with a Night Hag. The deal was that the Night Hag would provide him with a yearly supply of a restoration potion to suppress his daughter's magical illness, in exchange for exotic pets that Clease would provide. Clease admits to not fulfilling his end of the bargain.
Clease explained that his daughter's magical sickness has not been successfully cured by any of the spellcasters he has hired, and that this is what caused him to begin hunting in the first place. He says it pains him to be away from his daughter, who is being sheltered on the Ascent of War.
During the walk, he also inquired about the strangeness of the group. He stated that he thought the Elves' god was heartless and uncaring to have abandoned them on this realm, and that Aryssa too was a cruel god. Aryssa, he reasoned, had done nothing for humans or dragonborn but create them to fight and die for it, "and it has given us nothing but mortal foes as far as the eye can see."
The Dragonborn did not see much wrong with that.
The druid and bard didn't provide too many counterpoints, leading Clease to conclude, as seemed to be his initial opinion, that, "The gods are shit."
After being shown the way, Clease returned to camp, and the party attacked the owlbear cave. They used the Pass Without Trace spell to avoid a magical bear guardian made out of enchanted wood. Upon entering the cave, they felt a tingly sensation, but pressed on.
They made it to the basement and attempted to Speak with Animals to an Owlbear that was wearing barding. Unfortunately, at some point, they mentioned Clease, and the owlbear went in to a frenzy. The party killed all five owlbears, after initially attempting to tame the armored owlbear. Because taming animals is what the party does now, I guess.
While butchering the animals, a beautiful elven woman flew in to the cave, bordering on a rage. She was initially angry with the party for killing her pets. She introduced herself as Hurvaya. She and the party talked, and came to the agreement that the party would leave the eggs and never come back, but could take the dead owlbears. When the party mentioned that the river dragonborn had told them Clease could be coming, because the party pushes their luck whenever, wherever they are, the woman became angry, rippling with magic. She agreed to give the party one of the owlbear eggs if they came back with information about Clease.
The party then returned to the shadows because Pass Without Trace lasts a really, really long time. They sent an animal messenger back to camp to warn Clease, and Carnyx met them when they got back to camp to talk with magical messages, because Magic.
The party said they were going to go on to the Elven Trade Post so that if the woman was following them, they wouldn't lead her to Clease. Carnyx told them that Hurvaya was the Night Hag. Something that actually somehow surprised the party despite the Charisma saves, pets and unbridled, poorly suppressed murderous rage at the mention of Clease's name.
Carnyx arranged to have the sorcerer and goliath meet the party on the way to the Elven trading post and the adventure ended with the party somehow discretely delivering the owlbear parts, but I'm not going to argue with it because they used Pass Without Trace again, and that +10 and magic really justifies a lot.