I'm not in the target audience for this book, so I'm going to try to review this in terms of how I would have liked it when I was (a little) younger.I think Troubletwisters can be summed up rather quickly as simple - simple in plot, characterisation, language and execution. Which wouldn't necessarily be a bad thing, considering the intended age of the readership, but I think the book is condescending towards them. The authors uncharacteristically assume that their audience wants stereotypical characters, cartoonish villains and sluggish plot. But readers accustomed to Rowling, Wynne Jones and Nix's The Old Kingdom Chronicles will be severely disappointed in the lack of sophistication in Troubletwisters.The protagonists are chosen such that the book appeals, in theory, equally to boys and girls - the twins Jack and Jaide conform to every stereotype available, as does their absentee father, overly cautious mother, and batty, mysterious grandmother. The cats, who start talking half way through the book, quickly become parental figures who help the twins on their quest while the adults flounder.However, I think the characterisation would have worked if it hadn't been for the plot. After an explosive beginning, the book stagnates until the final 100 pages, and readers are treated to the hum-drum lives of the protagonists as they attempt to undermine the authority of the grandmother they instantly dislike for a majority of the novel.The concept behind the book is intriguing, and appealing enough to hook me for the next book. I think where the book fails is in grounding the conflict between Good and Evil in a way that seems plausible - the forces of Good exist because they have to, and Evil is literally an amorphous concept that wants to destroy for destruction's sake. Once I got over this hurdle, the rest of the book was fairly enjoyable. And I want to see the kids figure out the secrets that have been hinted at in this book.I wanted to like Troubletwisters a lot, and I even wanted to put myself in a twelve-year-old's shoes to achieve this. But, ultimately, I find myself profoundly disappointed that these two eminently qualified Australian authors have served up something so inferior to their other works. I can only hope that they stop underestimating their audience in the future.You can read more of my reviews at Speculating on SpecFic.