Adding to what's already been said:
You have two shifts of POV in these chapters that seem out of place (and aren't really necessary, imo). The first one occurs after Abby is first introduced and Will shouts at her, after which a paragraph or so is narrated from Melor's perspective.
The second one is when Dezkin drinks the potion that lets him speak intelligibly, when he briefly is the POV character.
Speaking of that potion, and considering that the apparent lack of limitations of your magic system has already been mentioned, I think you could avert that impression by making the potion not quite as powerful. By making its only effect be that one can understand foreign languages, for instance. Then everyone would have to drink it, and it wouldn't seem so much like "oh, look, a universal translator. How convenient."
I also thought the discrepancy in the townspeople's knowledge strange. On the one hand, they apparently don't know the insanely powerful necromancer who could defeat any army and rain destruction upon his foes, but on the other, they do know enough about his plans to see that they won't come to fruition without the book that nobody can read. That they have to be told about Haldor also makes him seem like not much of a threat, which in turn makes the situation lose much of its immediacy and tension.
And then there's the fact that at first Dezkin is very important to the necromancer's plans, later it's the books that are important, but then it's Dezkin again, and Will has to hide him...
The eternal menace that is show vs tell has already been mentioned I think. The only instance of that which I consciously picked up was "it took a big show of force from the constables".
I stumbled over the word "physikk", mainly because it made me wonder why he isn't simply called a physician.
And the last point on my list is the apparently completely unobserved influx of large bodies of armed men into a relatively small area - that is to say, how do they get around without someone seeing them? I strongly suspect there's an explanation for that in your magic-rich world, so don't forget to put that into one of the next chapters.
The entire story about Haldor and the accompanying infodump positively begs for a prologue, in which you could also demonstrate just how powerful he actually is, for instance.
Apart from those things there's absolutely nothing at fault. Your writing makes for an enjoyable read, the story is interesting, and your setting is just strange enough to uphold a certain level of curiosity. Well done indeed.
