When the Dragonborn enters the cave, he sits at a table just inside and as he is blind, it is easy to sneak past him if the skill is high enough. On the table before him lies Ulfr's Book, which contains blank pages. It can be taken in front of Ulfr without him noticing.
If he hears them approach, a short dialogue with optional replies starts. Ulfr will ask if the Dragonborn is "Rodulf," the bandit outside. They can either say that they are, which will lead to Ulfr telling them "The boss was looking for you," allowing passage without a fight. Or, the Dragonborn can say "No, he's dead, and you're next." The former option will lead to an easy fight, or flee at higher player level, the latter results in alluring attentions from his allies.
If the former is chosen, Ulfr will remain passive even as the rest of his clan is killed. Upon leaving the caves the Dragonborn can speak to Ulfr, but all he will say is "Good luck out there."
"Eh? Who's there? Rodulf, that you?"
- Yeah. "Boss was looking for you - said he'd be up at the summit. Better not keep him waiting."
- He's dead. You're next. "Hey! Somebody get down here! Help!"
- "Good luck out there."
- Although Ulfr is supposed to be blind, he behaves exactly the same as any other character with the bare minimum detection threshold.
- Even if no noise is made on approach, he will detect the Dragonborn if they enter his visual plane.
- His head will follow the Dragonborn around if they stand in front of him.
- Ulfr does not need to be killed to mark White River Watch as cleared.