Anna is moving in with Charles and learning what having a real pack is like. The mating bond just isn't connecting between her and Charles though because of what her old pack leader did to her. (rape and abuse) Since she's an Omega (basically a werewolf who transcends the dominant/submissive code as well as having the ability to soothe the inner wolf on others) the abuse hit her harder. There's also a rouge wolf on the loose and a sinister witch from a pack member's past.
The plot is a little slower in the beginning but picks up right away after that. The tone of the book is more subdued and nervous but that's perfect for Anna's story.