As you head north and discover Waukeen's rest in Baldur's Gate 3, you might notice that everything is on fire. In the same building where you rescue the counsellor, you can choose to rescue a man, Benryn, who's trapped beneath the rubble. Get him to safety and soon you'll stumble across his wife's body and will mention that they had a fight about a dowry for her sister.
In this guide, I'll talk you through how to find that dowry and what you should do with it.
Where to find Merileth's body and the dowry
Before you get started with this, it would be helpful to equip the Amulet of Lost Voices or cast Speak with Dead to have a quick chat with Merileth once you've found her.
You can get to Waukeen's Rest by heading north from the Blighted Village waypoint, jumping across the bridge, then heading northwest up the road. Once you've rescued Benryn—you should hopefully pass a perception check to see that opening one of the doors is gonna lead to a bad time—break down the door behind him and cross into the next building to find Merileth's body. You can leave your party outside and take Karlach in to do this as she has fire resistance and a lot of strength, making it a lot easier.
Use the Speak with Dead spell to talk with Merileth and she'll reveal that the dowry is hidden in the barn. Jump down to the lower level and head through the archway to find three barns. Head into the one on your right that has a giant haystack in it and interact with it to roll a perception check. A chest should pop out containing the dowry ring.
The right thing to do here is give Benryn the ring—man's just lost his wife after all—but you can pocket it if you wish and sell it later. Astarion disapproves if you hand the ring over, but don't let one disappointed vampire stop you.