Wizard. Black. Slytherin. Death Eater. Regulus has lived his whole life under a pile of labels and expectations. Things to uphold... and, due to the Dark Lord's critical misunderstanding of how Regulus had prioritized certain loyalties, at one time things to betray.

"I don't know what that is," is his honest answer. He finds it ironic, too. Untangling what Voldemort was up to had honed a talent he hadn't before realized for figuring out the motives of others... but it was no help at all in figuring out himself.