Wingbearer. Book 2, Wingborn

"After her encounter with the Witch-Queen, Zuli is shaken--but feels more determined than ever to find out what's happening to the bird spirits. Armed with new information about her identity, she mounts a daring escape from a merchant airship and takes off with Frowly and Orien by her side. But the more she tries to solve the mysteries swirling around herself, the more she's drawn to legends about the mythical Siric, who have long since disappear...