FAIRY TAIL Blue Mistral Vol 3

From the Kodansha edition

A DRAGON SLAYER IN DISGUISE When Fairy Tail gets word of a dragon kidnapping young omen in the town of AIya, Wendy doesn't hesitate to investigate...disguised as a boy! However, she doesn't get far before Carla suddenly starts acting strange and runs away. To find the missing girls and save Carla, Wendy will have to go on a dangerous adventure full of magic and intrigue. Will she be able to get to the bottom of this eerie turn of events all on her own?

Source: Anime News Network Encyclopedia