Dire Bound. Alma de lobo

Meryn Cooper has always hated the Bonded, elite warriors who form mental connections with the enormous, ferocious direwolves they ride. While they live in luxury, she struggles to lift her family out of poverty. However, when the enemy kidnaps her younger sister, Saela, Meryn's world crumbles. Desperate to reach the front lines and save her, she enlists in the army to face the deadly Bonding Trials, where any mistake will cost her her life. She must survive four months of training bonded to a wild direwolf that refuses to communicate, while the other apprentices are dying to spill her blood, and her cold, attractive instructor, Therion Stark, seems more than willing to punish her for the slightest sign of weakness. Everything is a competition, and everyone is her enemy. Except, perhaps, the prince, whose interest in Meryn makes her a target to be defeated. For in the castle, every smile hides a knife, and every corridor harbors a secret.