sentences:  In the second book Ari receives wings, which makes him envy the Flock; his wings are clumsier and do not fold as neatly as theirs do.The Erasers were killed by the white coats at the beginning of the third book because they were unsuccessful; although replaced by the Flyboys, they reappear in "".Also, in Nevermore, Fang's gang is shown to be fighting them.