Narfi is a beggar living in Ivarstead. He's the guy that lives in the crappy house across the stream. Since he's already semi-isolated; it makes our job that much easier. I like to wait until night, then head over there. Be sure to sneak so you can assure yourself that no one can see you; then one good sneak attack will take him out.
If this is your third contract you should head back to the Sanctuary and report to Nazir. When you get there you'll see a new (and big) crate in the den, as well as a jester named Cicero. Hmm, it seems that the Night Mother is now here. Astrid will talk to you afterwards and give you your newest contract, triggering the next quest: " Mourning Never Comes ".
Be sure to talk to Nazir to turn in this and the other assassination quests. This contract is worth 500 Gold .