Villagers in Karthgad speak of an old barrow that sits atop a nearby mountain. Inquiring further, (add a topic for "been there in years" the villagers will say the place has an ominous reputation, and that someone ought to check it out.You know the cliffside where the Bear Clan’s ancestral barrow is? To the west, on Karthgad's outskirts? Few know there's actually a second barrow there too, up on the mountaintop. I don't think anyone's been there in years.
Investigating Bathmvall Barrow, the player will find and kill too vampires. Returning to the village, the villagers will thank the player for the deed and direct him or her to the Thane, who will reward the player. If they player talks to the Bear Clan about the vampires, they'll only scuff and tell him or her to buzz off.
Note: Delete the current little secret duplicating the above response.What’s that? You found vampires in Bathmvall? That old barrow up in mountains near the village? How awful! You have our thanks for slaying those foul creatures. You should go the thane for a reward.
After discussion on Discord vampires to be Khulari "A Redguard vampire clan specific to the Reach in SHOTN". Intelligent vampires who probably talk to you and offer vampirism in exchange for something if you wish. Maybe they could talk about what its like to be a Vampire in the West.