The covers link to The Tattered Cover (to promote indie bookstores a bit) in case you'd like more info. Here's book eight:

What did I love about this? Honestly, just about everything. I loved the relationship between the sisters. I loved the relationship between both Scarlett and Rosie and Silas. I loved the tension of Scarlett's agonizing drive to rid the world of evil wolves. The mystery was fantastic, and I read the entire book in one sitting (gulping it down).
The story: Scarlett fights werewolves, and in one of those fights (the one which saved her sister's life), she lost her eye. Rosie has felt indebted to her sister all her life, and because of that, she also trains to fight, even though (deep down) she doesn't want to spend her life fighting. When Scarlett, Rosie and Silas (their third fighter) realize they need to travel to find the most dangerous wolf, their carefully structured lives begin to crumble -- and both Scarlett and Rosie have choices to make which will completely alter their futures.
I'd recommend this to everyone (clearly), but especially to those who love familial relationships, sweet romances, and a nice mystery.