Finished this last night. I enjoyed it!
This took place in the demon world, because the summoner, Kara Gillian, was summoned by the demonic lord Mzatal. It was a lot of info, finally revealing everything we've been wondering about. Now, I know a few didn't enjoy this UF-now-Fantasy novel, but it was a nice step in Kara's life. And yes, she's different, but I think it was necessary, because it's toughened her up and taught her a lesson in trusting blindly (well...as blindly as a detective can trust).
I was completely shocked at what happened, and it kind of hit me out of nowhere- I hadn't seen any foreshadowing that would warn me of this!!!
So this follows Sins of the Demon, and she's much powerful now. All the characters I knew are now looked at from a different perspective. I don't think you'll be disappointed with this one :) But first start at the beginning, of course!