Enjoyable read that kept me gripped to the end. Anthony Horowitz is one of a kind and this is intricately written and ingenious in its design. Another reviewer mentioned animal abuse - this is an extreme interpretation of a necessary part of the plot. No gruesome details are mentioned and it is described only in oblique terms. I say this as someone who is a massive animal lover and very averse to violence in books, graphic or otherwise. Don’t let this put you off, it’s hardly worth mentioning. 5 stars.