Moon Over Soho by Ben Aaronovitch

The second in the Peter Grant series this is a fun magic adventure story about an apprentice wizard working for a top secret department within the Met police.  It's a bit silly and very easy to read but the plot is good fun, fast paced and not so ridiculous that you can't legitimately enjoy it.  The main character, Peter, is likeable and as realistic as it is possible for a policeman wizard to be.  The writing is good, although some of the metaphors are stretched a bit far, and the dialogue natural but it's really the plot that makes this such an engaging book.  It's basically Harry Potter for adults (and it is definitely for adults – it is really rather rude in places).