"I know. I should have-" It was as close to an apology as Regulus would get, considering that prior to that they hadn't talked for year. "You didn't do anything, Sirius. I made choices to keep us safe, to keep our world safe and that included disappearing."
He tilted his head until his cheek was resting against Sirius. "I didn't hide before I was afraid of the trials. I was hiding because after the Dark Lord, there were others continuing his work, trying to achieve immortality. Dumbledore didn't know. He had no fucking clue, Sirius, no matter how much he likes to play the omnipotent God. Someone needed to do something, and I'm the only one who knew what to do. This is why I was hiding. It's why I reappeared and why there are five wizards in Azkaban. It's not something people know and something you can't tell anyone, because our lives would be at risk - mine and yours, but I'm trusting you with the truth, because I don't want you to think that this is somehow your fault."