Agent Skully at New Hearthglen has asked you to steal the image of an Onslaught Raven Priest. Return the Banshee's Magic Mirror to her when you have done so.
You may wonder how I can maintain this guise; I use a magic mirror that was loaned to me by the spy mistress.
It only has so much power in it, but I think there's enough for the both of us. Here, take it. I want you to use it to impersonate one of the Onslaught raven priests.
Be quick about it... I have no idea how long my glamour will last while you have the mirror.
Realize that you won't immediately be perfectly disguised, so don't count on it being foolproof until I've had a chance to help you.