That's a new one for Jamie. He blinks rather rapidly. "Bene Gesserit?" Don't get him wrong, he knows the term - he's talked to a couple of them, after all. But...

"I didna realize ye could study to become one if ye weren't from their world. Don't ye have to take their spice drug or something?" He's a little fuzzy on the details, and looks at Katara with a rather puzzled expression.