i quote from Mr Persons bloodmoon FAQ Link
Quest 4: Prove Your Wisdom
This quest is really fun. You are sent to investigate a crime. Rigmor
claims thet Engar Ice-Mane stole his furs. Gather information in this order:
First talk to a non-guard random person in the Skaal about Engar.
Then talk to Engar's wife (Risi Ice-Mane) about Engar and Rigmor.
Finally, talk to Rigmor about Risi Ice-Mane
After you have done that, return to the Ice-Mane abode and collect a note under
the pillow. Confront Risi about it, and she'll admit to an affair with Rigmor.
Talk to Rigmor about the whole affair and he'll admit to his crime. Lead him
to the greathall, and speak to Heart-Fang. You must decide Rigmor's fate now.
Go ahead and pick sacrifice - it's the nicer thing to do.
Bring Rigmor with you outside and over to the wolf pen. Be a nice helpful boy
and open up the pen door. Rigmor will walk inside and put up a pathetic fight
against the wolves. It's better this way.