Iron Flame by Rebecca Yarros, Book, Softcover

Now the real training begins, and Violet’s already wondering how she’ll get through. It’s not just that it’s grueling and maliciously brutal, or even that it’s designed to stretch the riders’ capacity for pain beyond endurance. It’s the new vice commandant, who’s made it his personal mission to teach Violet exactly how powerless she is–unless she betrays the man she loves.