In the interest of full disclosure, I've read this series out of order. I read the first comic book story, then #2 in terms of the novels.
Midnight Riot introduces us to the character of Peter Grant, who is a copper who can see ghosts but is most likely going to get detailed to data entry. Lucky for him, that sees ghosts thing saves him for a dull life in front of computer during police work he much rather push off on his friend Leslie who he wants to shag. She doesn't mind doing the grunt work even though she seems like she is a better copper, at least in terms of dealing with real people.
Anyway, Grant finds himself working with a wizard who is not Voldemort or Harry Potter or Dumbledore. His name is Nightengale, and he has a maid/something named Molly who is very senesitve about her teeth. Grant also finds himself dealing with the embodiments/spirits/gods of the various rivers and what not of London.
It is the folkloric and river beings of London that make the book most interesting. Honesty, the idea of Mama Thames as a black woman is wonderful, espeically considering the immigrantation issues and debates. I love it. Though there is a bit about the rivers that is a little, iffy, for me. Beverly is one of Mama Thames' daughters and is first described as a teenager. Then Peter has a wet dream about her. Now, I am sorry. I get Peter isn't that far out of his teens himself and that teenager can mean 18 or 19 as well. But for much of the book Beverly comes across as younger than that. I am well aware that her actual age can be far greater, but there is something about icky about Peter's reaction. Quite honesty, if he paused for just a sec to examine the whole issue I would've felt better. Additionally, I'm sorry, but I like Tyburn who is simply doing what she should be doing so why is she the bitch?
Still, enjoyable for the use of folklore and myth. There is some nice humor, and Peter grows a bit.