I'm playing as King of Vampire Coast and I've created a mercenary band with one of my sons as leader. I have just hired that son for a war and loaded his troops onto galleys. While on the water, I'm getting events that tells me my mercenary son(the one of my ship) has been spotted and asks me if I want to raise the black flag. Also my mercenary son has already been imprisoned by one of my other sons who I suppose has also gotten this event.