An Ember In The Ashes by Sabaa Tahir
In a brutal, Rome-like fantasy world, a young Scholar girl named Laia goes on a dangerous mission to save her brother from the clutches of the oppressive Martial Empire. To do so, she infiltrates the Empire's premier military academy as a slave, where she meets Elias, one of the academy's finest soldiers, who is secretly as eager to escape the tyranny and corruption of the military as she is. Their fates become intertwined as they both seek freedom and justice, navigating a world rife with violence, betrayal, and dark magic. The story is a gripping tale of resistance, survival, and the quest for personal redemption.