This...wow, that makes me laugh so hard. 
Based on the average Crack Theory around here, that one has more "Major Storyline Stuff" packed in per word than nearly any other book in the series. I'd say Cold Days tops it, Grave Peril by pure lasting implication, maybe not Changes (oddly enough?), on the fence about Ghost Story...
Sure if you are wanting hints -etc.
But overall? Its about madness at a con, a trip into faerie worlds and then a white council meeting. While there are hints and stuff dropped, that is alot lighter than some major story world upsetting/heavier things such as defining what it means to be the White Knight, throw down with Erlking/ Wild Hunt, dealing with the potential destruction of the White Council (turn coat) vs figuring out who is trying to kill women close to a porn director (blood rites)
Cold Days overall is a heist story, there is alot less world shaking events in it then say summer knight which setup how the White Council works -proceedurals etc.
Does that make sense by what I mean of lighter to heavier?
Peace Talks is showing the supernatural big wigs all facing up, and has to have an event that both makes Mab sweat, and be something at such a level that seems justified as an event that causes Mab to sweat knowing as we do now, more of what Mab is. In many ways similar to how Changes fundamentally changed things for Harry. He couldnt go back to his old life no matter what. -Car was flattened, apartment burned down,and a new building is there. -- no going back points.
Structurally, Ive a feeling this is heaviest structure-wise until the Trilogy.
