I read Frostbite - the first of David Wellington's werewolf trilogy - and really liked it. I did not enjoy this one nearly as much. The addition of a more supernatural aspect to the Zombie premise was a bit too much. I would have preferred to stick with the straight-up zombie story rather than adding in Mael and his band of mummies.
The characters, other than Ayaan, are not really very likable and don't make you anxious for everything to turn out okay for them.
I will read others by Wellington -- and may even finish this trilogy as I think it was his earliest one and that may account for the issues in the first book. Unfortunately, it will be later as there are others in the queue that have been more interesting/enjoyable lately.