Mosley is the chief of the bandits who kidnapped Eileen Bensley during the quest A Daughter Ransomed. The Warden can persuade him to give him the girl before he lends him the money. If it successes, Mosley will ask for the ransom. The warden then has the choice. Either he gives him the ransom, or not. In that case, a fight starts and Mosley is killed by the party while Eileen Bensley flees.
At the end, Mosley is either dead or alive, depending on the choice of the warden.