The Sisters may be found anywhere from street corners, where they offer to tell ones future for a few pennies, to those who appear to be working for the service of a lord. It is said that they go where they will, when they will they work for who they choose, not for who chooses them.
A large vertical cave has a constant, strong wind blowing out of it from the bowels of the earth. If one was to jump into the currents they would have a controlled ascent on the winds till they reached a height where their weight and the winds force reached equilibrium. Impossible to climb down naturally. What is it? Natural winds from the earth or a complex magical protection for an underground lair?