Rissa needs to earn her freedom, and in the Riciliy Empire, that means becoming a gladiator in the Coliseum. Luckily, she likes fighting, and though small, she is aggressive, unremitting, and not afraid of violence.
Dahl, one of the Top Five gladiators in the Coliseum, is a troll of a man, who is a puppy at heart. He's fascinated by this prickly new gladiator, is happy to train with her and help her navigate the politics that are as much a part of being a gladiator as fighting.
She will need his help, because while death in the arena is rare, it does happen, and for Rissa, the greater threat comes from outside the Coliseum walls. There are important people who would prefer to see her dead than free, because if she speaks out about who she really is, what happened to her, and what the nobles of Riciliy have done, the entire Empire might be shaken to its foundation.