The Ring of Five (by Eoin Mcnamee)

Danny Caulfield isn't happy when he finds out his parents are sending him to Heston Oaks, a boarding school for snobs in some out-of-the-way place. He's even less happy when he's kidnapped, taken to a mysterious place, and treated like a naughty schoolboy. When he finds out it's a school for spies, and he's been "chosen" for something, he decides to run away. He learns there are two worlds, vying for power over each other. When he can't leave, and when attempts are made on his life, he discovers that the dark side needs him. With the help of his new friends, including the winged Les, he must deny the allure of the dark side, and save his world.

- Review by Abby