This is the long waited final instalment of this series. Those buying it for younger readers should be aware that it is definitely aimed at older youngsters than the Alex Rider series. This final book has scenes of explicit and disturbing violence, more than the anticipated beatings, so be aware.
The story is told from the points of view of a number of the main characters, principally the five but also others. This helps to break up what is an extremely long book. That is probably one of my criticisms, it is really too long. Presumably Anthony Horowitz also understands this because as each character takes up the narrative there is a short reminder of what occurred the last time they were narrating.
The story is very exciting, intended to be many layered, a bit too keen to be didactic and moralistic. Horowitz also seems keen to demonstrate his anti religion stance. I didn't really like the end, but will be interested to see what others think. I think that the book has been written to be adapted into a film, not a criticism but an observation.
I enjoyed the different depictions of a post apocalyptic world, they were credible, although London was weakest as if there was a need to get on at that point with the story. In fact on reflection there are a few points when the story feels it has run out of steam or as if like in centuries gone past a painter allowed an apprentice to work on famous paintings. Part of this book has that same feeling that small parts have been handed over to other lesser writers.
However, all the ends are tied and at least there is no doubt that this is the end if the series.