A look into Trull Sengar's past

When I began this book, I was quickly confused. I was pleased to see the familiar character, Trull Sengar, but found him to be in circumstances completely different than those in which we'd left him. I had to do a bit of googling to confirm my suspicion: This book takes place before the previous book. Somewhere around the same time as book two or so, from what I can gather. There doesn't seem to be complete agreement about it in the forums. So, this book gives us a peak into more detailed background for Trull Sengar, and introduces a number of other characters who quickly become complex and compelling.
As much as I've enjoyed this author's writing, I started to find myself a bit distracted by his overuse of sentence fragments. I'm a fan of sentence fragments. I think they can add a great deal of impact when used skillfully, but I felt I was seeing them far too often, and unnecessarily.
Despite that issue above, I found every aspect of this book engaging. In past books, I was less thrilled with certain POVs, like Karsa Orlong. Never again the hundreds of pages of Karsa Orlong, please! Anyway, where this book was concerned, I actually found myself caring about all of the POV characters. I was momentarily disappointed each time I ended someone's scene, only to be quickly drawn into the next, happily pulled down the rabbit hole.
I'm trying to figure out why I'm feeling more drained after reading this one than the others. My first thought was that the ending was darker than the others, but then I consider what happened between Tavore and Felisin in the previous book, and you don't get much more tragic than that. It could be that the ending in this one had fewer uplifting moments to balance out the tragedy, but I'm not sure that's true either. There was still some pretty good payoff in the end, with regard to at least a couple of people. But I'm left with more of a hopeless feeling than the previous books left me with. That must be it. So, in that way, I suppose this one was darker.
There were a few questions that were left unanswered, and I really hope to see those answers in the next few books.