I think this book is my favorite out of them, mostly because it's less about an adventure and more about the characters finding their place and spending time together. I must admit I didn't care for Shepard and Penny's drama and romance (even though I really like Penny as a character). I wish instead we'd gotten more of Agatha and Niamh, who were truly a highlight in this book. I didn't think Agatha would become my favorite character, but here we are. All in all, this book was very fun to read.
Also,

living among the goats and having a girlfriend like Niamh,

Agatha is living the dream. Good for her.