One Wish (13 Treasures Trilogy)

Tanya Fairchild may look like an ordinary twelve-year-old, but her life is anything but ordinary. After all, Tanya can see fairies. And real fairies are nothing like the ones in books..... When Tanya and her mother arrive in the bustling seaside town of Spinney Wicket, they have no idea what's in store for their summer vacation. Tanya soon meets Ratty, a young boy who shares her ability to see fairies. When Ratty goes missing, Tanya discovers her new friend has another extraordinary ability--an ability that has the potential to destroy them both.