I loved "Ill Wind", the first in this series, and immediately after finishing it bought the next 3 books in the series.
Heat Stroke, although a very good book (thus the 5 stars) didn't quite work as well for me - it felt rather like a linking book, with a far more `up in the air' ending. It was a relief to me to know that I had the third book already so could continue the story.
Caine's world is more interesting in this book as we start to learn what being a Djinn entails. Joanne is settling into her new life and existence as a Djinn and having to learn, very rapidly, how to control her new powers. We meet new characters, including the almost-deity Jonathan, as well as meeting again some of the previous characters like Paul and Lewis. Caine isn't afraid to kill off some of her characters (I'm not going to spoil it by saying who), although I keep being rather worried for David. We have so many hints at possible love-interest between Joanne and Lewis, Joanne and Paul, that you wonder when David's going to get the chop. Fortunately not in this book. You can spend a lot of time thinking about the interesting side issue as to whether Djinn have the same levels of morality as humans when they can be commanded to kill people, to rape people - perhaps this will be further explored in the next books.
The main `threat that involves Joanne saving the day' in this book I found a little confusing. Yes, the twinkly sparkly things were rather different than a dragon or evil despot, but I didn't really understand how it all worked. Perhaps reading the book again will help me to get it straight in my mind. Nevertheless, the middle section of the book dragged a little to me, as Joanne whizzes around the world and Djinn world finding things out and trying to solve problems with her huge power but very limited understanding of the situation. Once again, she comes across very much as a Stephanie Plum character (from Janet Evanovich's very funny crime novels) and I love her sassy nature. She's an excellent heroine.
The end of the book definitely improved, and we were left dangling on a precipice of an extremely serious situation that no doubt Joanne, David and Lewis will be doing their utmost to fix in the next book.
I did like this book, but I feel that it perhaps didn't have quite the immediacy of her first offering. The writing is great fun as always, well-paced and humorous in many places, and so it is worth a read.