"Oracle of Philadelphia" is the first book by Elizabeth Corrigan, and starts the "Earthbound Angels" series of – I guess – Urban Fantasy novels. It is a fairly short book which starts indifferently but finds its feet about a third of the way through and shrugs off the early structural difficulties to give an entertaining tale.
The book is told in the first person from the viewpoint of Carrie, a human who became immortal due to a bargain with the Devil (not her bargain, it must be said), and is possessed of supernatural powers; in particular, she can read minds. When the book begins, she's living in Philadelphia and running one of the worst – if not the worst – diner in the city, and occasionally giving advice to mortals and immortals. The plot of the book revolves around her trying to save a mortal, Sebastian, from a bargain with a demon he entered into to save his sister, and sees her entering Hell several times and bargaining with the demons there.
As Carrie is thousands of years old, she has quite a bit of history. Corrigan tells the story with frequent diversions into Carrie's past history, generally relating how she met some of the other key characters. This is the key problem with the early part of the book: it diverts too much into the past and doesn't allow the current story to move forward. By chapter 5, three of the chapters have been relating events in the past! The balance gets a lot better later on, and the book is at its best when Carrie is in Hell, dealing with the various demons/fallen angels who rule there.
A highlight of the book is the mythology that Corrigan is creating; the relationships between the various angels and demons in the book are fascinating. A key idea is that angels can fall in love but not out of love, and this creates a few tragic characters that I hope get further developed as the series progresses.
The resolution to the book, which involves a major revelation, is not quite as strong as it could be; in particular, the characters' reactions to it are somewhat muted. Certainly the book has been more about character then plot, but we don't really get enough of a reaction from Carrie's nearest and dearest to this revelation. It's not horrible by any means, and I, as the reader, was very pleased by the twist, but aspects of it just feel wrong to me.
Overall, the book isn't without its flaws, but it was an enjoyable read with some excellent characters and mythology. I'll keep my eye out for the sequel.