Fairy Tail: The Beautiful Beast (Book 1 of The Wolf's Tail series)

Lucy, Natsu, Happy, Gray, and Erza all go on a mission together. But when they get there, the plan they had gets completely turned upside down when one of them gets hurt, to the point of death. And when they rush back home to get help, they look furture into the attack and find that there's nothing wrong. Except deep...