Wings of Fire: The Dark Secret

This is likely referring to 'The Dark Secret' by Tui T. Sutherland, the fourth book in the Wings of Fire series. The story follows Starflight, a young NightWing dragon who discovers disturbing truths about his tribe's history and their hidden volcanic island home. The book explores themes of truth versus deception, courage in facing difficult realities, and the importance of standing up against injustice. As with other Wings of Fire books, it features diverse dragon characters and emphasizes friendship, loyalty, and moral decision-making in the face of complex political situations.