
It has been a while since I read the novel and I didn't read the whole novel so I only remember a few stuff
Ishakan is going to kidnap Leah when she was in a carriage on the way to marry the margrave, he brought her to his kingdom and married (or hasn't yet) Leah. One day she had to go back to her kingdom, if I wasn't wrong she thought that Ishakan was dead.
The brother lust after her, even though he was already married to a lady, he still wanted Leah. He expressed the feeling to his mother and his mother, who's some sort of a witch gave in and let him 'have' her. The king, Leah's father was under the queen's spell this whole time.