Tara K. Harper's Wolfwalker series is among the best science fiction I've ever read. I love her characters, the unique world she's created, and the story lines she's developed. Wolf's Bane, however, does not at all live up to the rest of the books in the series.
I found this book to be unnecessarily brutal. Bad things kept happening one after another, to the point that I felt it was put in more for shock value than anything else. Had there been longer breaks in between the horrible parts, it might have been better.
Most of the book is spent on how depressed Dion is because of the tragedies she's had to go through. This is completely understandable, but it makes for a boring story. Instead of the adventure I was expecting, it was flat. Either Dion is immersing herself in the wolves or her friends are griping to each other about who should snap her out of her unhealthy depression.
The ending is the worst, though. The entire book might have been redeemed if the ending had been better. However, after 300 pages of set-up, the last 50 pages weren't enough. There was hardly a resolution. Dion ends up feeling better about her life and where it's headed, but after wanting concrete answers for the entire novel, she settles for something far less than that.
Despite all this, I did get some enjoyment out of it. It was nice to revisit the world and the characters. Harper does a great job in giving them different traits as they all age. Dion is no longer than infallible wolfwalker, and Aranur is even beginning to slow down a bit. This novel does shed a bit more light on Grayheart and the other books set in the future, but I don't think that the time spent getting through it is worth the bits of enlightenment we get.
If you're reading the series, I would say skip this one entirely. You can pretty much figure out its content from her other novels set in the future and you will save yourself some time and a lot of frustration.