Fafnir

Fafnir was a male Nord and a murderer in the Dark Brotherhood. He is your Dark Brotherhood liaison for the quest Whodunit?. He gives you your instructions upon arriving outside of Summitmist Manor. In short, he says after you go in, he will lock the door and you won't come back outside until all of the guests have been "taken care of", dead. After you enter the manor, you will never see him again in the game. It is likely that Fafnir is a member at a different Dark Brotherhood Sanctuary at some other location in Cyrodiil or abroad. (He states that he and the player "share the same Mother.")

Related quests

 * Whodunit?