I see this as a spin off series of Patricia Briggs' Mercy Thompson sereis. I also think this one has a whole lot more "relationship" and "romance" issues going on. Not in a bad way by any means, just that the relationship between the two main characters seems to be a main vein that runs through the entire story. Where as the Mercy Thompson series has romance but I don't feel like its the main focus. 
 This series really should be read along with the other series to get the full depth of everything thats going on (Just in my opinion) though it isn't necessary to read both. But it does offer a lot of insight into the pack of werewolves that Mercy Thompson was raised in. 
 Lovers of werewolf fantasy will seriously enjoy this series.