All in all, i think this was very well done.
I agree with Hubay, the "cold ones" need a less generic name, even though we don't really know what they are/do yet.
One small thing that kinda bothered me a bit, though, was your use of language. Or rather, the mix of it. Some parts were spoken like they were out of a modern day setting (e.g. "My thanks, Jeffe. May your lips never miss the taste of my ass.") while others felt like they had a more archaic/old world feel (e.g. "Just be ware lest your pupils accidentally prick you instead.") and the mix back and forth just felt kinda odd. Overall, it was pretty good, but the two mentioned lines are the two that, to me, struck the most opposing cords.
The first example, also, brings up something else i'd like to mention, though this may be a preference thing. The swear word. As a disclaimer, I have no problem with swearing in books. However, modern day, common swear words to me feel really out of place in a medieval fantasy setting. I think it's better if you use a less-common equivalent, or preferably make up your own that sounds like it fits the rest of the language pattern. Like i said, this could just be personal preference, but to me, it feels really out of place, so take that as you will.