I forwent sleep to finish this - and that pushes things to a 5. Really got into it - the characters were well drawn (although I can't say I liked them all, they were intriguing). 
 Elena is a vampire hunter - although here it doesn't mean staking them, it means catching them to return the vamps to their angel masters so they can fulfill their 100 years of service (the price of immortality). In this world, for all intents and purposes, angels rule (there aren't any religious overtones, although if you can only deal with angels in the strict Christian sense, then this book isn't for you). 
 Raphael, New York's Archangel, needs Elena to find a vampire. The only problem is, its not a Human turned vampire, its an archangel turned vampire. Dealing with angels is risky business, and getting to know their secrets is riskier. Raphael is also very seductive and he's decided he wants Elena. Lots of action, some very hot scenes, good characters - its a winner. It's also probably the darkest, most UF-like PNR I've read in awhile.