Rufio is a breton pilgrim who has been staying at the Inn of Ill Omen. He has been staying there hiding out for weeks, aware that the Dark Brotherhood wants him dead.
He accidentally killed Claudius Arcadia's wife or daughter during an attempted rape and turned Claudius in for reciting the ‘Black Sacrament’ but when the guards arrested Claudius he’d already made contact with the Dark Brotherhood.
During the ‘purification’ quest the player is given a scroll to summon Rufio’s enraged ghost for aid.
"No! Please! I didn't mean to do it, you understand me? She struggled! I... I told her to just stay still, but she wouldn't listen! I had no choice!" -Rufio