It's not a secret that Charles was a slave, but it's also not a thing he talks about. It's a thing he'd confessed to Jack one night, when there had been a shipment of slaves in the harbor destined for the inland plantations. Charles had stared and then gone and drunk himself into a stupor. Jack had come to fish him out of a fight in the tavern and haul him back to his tent, stumbling and belligerent. He'd wiped Charles's brow, given him water, and said if I'm to be your keeper I at least deserve to know why you've gotten yourself into this state. And Charles had told him, words slurring together, not the specifics but the general idea.