Although it's not a new thing, I have noticed an increase lately in series of books of which any one in that series needs what went before and what comes after - meaning in short, no one book truly works as a standalone, and this is a problem with this book, The Magician. There's no real intro, it carries on from previous events from the previous book, and the ending is lame, really, because we / the readers, need the next to see the story through to its conclusion. For those who would say 'Well it is a series', then I would say that the likes of the individual Harry Potter books, any from the Mortal Engine series or His Dark Materials all have at least interim conclusions making them a satisfactory read on their own.
But that aside, the bulk of this book holds your interest through it being pacy, (although it needs to be as there's no depth to the characters either, not really). The book is mainly set in modern-day Paris and utilises the above (Notre Dame, Gargoyles etc) and below (The Catacombs and famed sewer system) of this great city quite well, and it is this which gives it its glue.
If a tale of magic featuring present-days kids, (Sophie and Josh Newman) who have a hidden heritage and who (carrying on from the first book) rub shoulders with the oft-used Nicholas Flamel and a hotch-potch of historical figures who here really do have the magical powers passed on through fable, as well as out and out fictional creatures from folk-lore is your thing, you will enjoy this. I apply this to kids as well as adults (although the real target is older kids, just a tad before acne and teen-grumpiness set in).
All in all, a good read just not a brilliant read.