So that heartless prince knows something... he already knew from the start that he might not be the crown prince which is why he poisoned her father... It's just disappointing that the duke is a spy I kinda liked him.
Based on today’s chapter it seems like he’s threatening or coercing him into being a double spy. Still doesn’t absolve him and oof is it gonna blindside the MC
So that heartless prince knows something... he already knew from the start that he might not be the crown prince which is why he poisoned her father... It's just disappointing that the duke is a spy I kinda liked him.