When Isobel's carriage was attacked, she didn't expect the bandit queen, Ravenna, to be behind the attack. The inhuman woman took her hostage and dragged her away, though she reassured her that Isobel would be released as soon as her father paid her ransom.
It didn't stop Isobel from feeling angry about it, and the fact that the other woman decided to flirt with her didn't help. And yet, Ravenna was incredibly gorgeous. Inhuman, yes, but stunning, and there was a secret about Isobel that most didn't know, and it made her react to the monster girl.