This is sort of but not really alternative history (alternative present?) - in the same way as a lot of urban fantasy is, for instance, and it's almost urban fantasy but not quite that either. I mean, it's set in London, but London here is not the character that it is in Neverwhere or the Rivers of London series, so straight fantasy it is I guess.

Basically, an orphan kid with magical powers is apprenticed to an older magician, and things turn to custard, largely because all magicians are dicks, including child-magicians. Their collective, overweening superiority complex has made an underclass of regular people, which I expect will be explored later in the trilogy, and has resulted in a murderous backbiting culture within magic as magicians all try to scramble their way to political power. Nathaniel, the kid in question, summons a djinni called Bartimaeus and has him carry out all sorts of dangerous shenanigans in his quest to one-up the rest. The book's told from both their perspectives - first person for Bartimaeus, and third person for Nathaniel, which makes it feel a bit choppy but never mind. I liked it well enough, though it didn't entirely grab me - mostly because I apparently have a set limit when it comes to liking these characters. For most of the book, I enjoyed the kid's chapters a lot and the djinni's were far less interesting to me. Then, quite close to the end, the situation entirely reversed itself. It seems I can't enjoy both at once, which is quite odd. Having a favourite point-of-view in a book with multiple points-of-view is normal, of course, but the strict seesaw effect between the two, in my experience at least, is not.