
So it's true - Catherine only took Annette in because Heiner asked her to and has been reporting on her to him this entire time. I understand why she did it, but imagine finding out the one person in the world you considered a friend was hired to take you in and has been lying to you this entire time. She's probably gonna feel really betrayed if anyone ever tells her.
Now he's probably going to have her reassigned or something so she can be moved from the frontlines. No way he just leaves her alone and lets her do her thing. He's way too obsessed to ever let her go completely.

Five bucks says Catherine took Annette in because Heiner asked her to, probably to help her brother out of jail or something like that, and told her to keep it a secret. She's probably been keeping tabs on her for him this whole time and that's why she feels guilty taking the money. That's also probably what they were talking about for so long when he came to the house.

Where and when exactly would she learn about what happens during war or anything about how rotten the kingdom is? They don't have phones, TV, or internet and it's not going to appear in any books or newspapers she's allowed to read. She's probably monitored and supervised 24/7 and has guards and attendants that follow her everywhere she goes. Heiner is a jackass who's taking his anger out on the wrong person. This backstory doesn't make me sympathize with him at all, it makes me think he's deranged and dangerous.
Honestly, at this point, I kinda want to see this end in the worst way possible for no other reason than I literally have no clue how the author thinks they could possibly make me root for the relationship. If you're going to make the male lead this terrible you might as well fully commit and have him just go full on villain instead of all this whining. Him dragging her back kicking and screaming is way more realistic than her ever deciding to go back to him of her own free will. There's no chance I would believe she would decide she loves him again or that she always loved him or something stupid like that, so just go full throttle with the toxicity. Trying to pretend it isn't toxic is where stories like these fail.
I believe it's more realistic that he hasn't gone 'fully villain'. He's the type of person you'd find irl, self absorbed with a victim martyr complex, unable to do anything but lie to themselves.