Things are slowly starting to look back up for Daron after the crisis he went through in book 3. He's loosening up, a bit, starting to talk, a bit, things with Ziggy are.... manageable? Ziggy's assholishness in book 3 is starting to make a bit more sense in retrospect, although communication between these two is still a minefield of things not said, things half said and things they think the other thinks, but does not say. There's a lot of trust that needs to be rebuilt and while it's not there yet, at least there's a glimmer of hope that someday it will.
In the meantime, they tour. And sometimes that's a little boring and repetitive, and sometimes tons of shit goes down. Just like some chapters are just moving the story along slowly and some chapters have paragraphs or sentences that just hit you over the head with a mallet of sheer fucking awesome.