The two men stared at each other from across a desk, never letting their eye contact drop as the seconds passed. The elderly man's expression was calm and unflappable as he waited for his young companion to speak. The air between them practically crackled with tension, which they both knew would snap at any moment.
"You ... you have the nerve, the unmitigated gall, to ask me why, Dumbledore?" Snarled an enraged Sirius Black, who was using every last remnant of his patience not to shout; after all, they were in the office of Madam Pomfrey after she had given them permission to use it for this private conversation. "I'll tell you why, old man. It's because the boy I trusted you to keep safe is traumatized beyond belief.
It's because he's been through more in two hours than many full-fledged adults have been through in their entire lifetimes. It's because you barely gave us any time together before you started barking instructions in my ear. It's because I've made too many mistakes. I've failed that boy his whole life, but I swear to Merlin, I'm not failing him again.
"Albus," he continued, all the anger seeming to deflate from his face as he let out a heartsick sigh. "I've always had the utmost respect for you. You never cared about where I came from, you let me fight for you and the cause despite the fact that my family are poisoned with greed, hatred, and pureblood mania. I know that the reason I didn't lose my soul a year ago was due to you instructing Harry and Hermione. But now .. you've got to understand that I need to stay with Harry. He needs me now more than ever. So I tell you, my answer is still no, and will remain no, Dumbledore. You can ask others to go and rally the old crowd. I'm staying right here where I'm needed most, with the godson I should have always protected."
As Sirius finished this last statement, a million thoughts ran through his mind, but the emotion that stuck out the most for him right now was guilt; endless, gnawing, suffocating guilt. For too long, he had failed to do the one thing Lily and James had ever asked of him: to take care of their little boy if anything happened to them. He remembered the moment when they had told him they were going to have a baby, and that they wanted him to be godfather.
At that moment, his heart had expanded, overpowered by a feeling of such love and protectiveness that it floored him. He hadn't even met the child yet, he had still been months away from arriving, but Sirius had already known he loved him, and he'd go to the depths of Hell itself to assure that this precious human being who was both Lily and James would not come to harm.
But when the moment arrived ... when the unthinkable had happened and his entire world had collapsed around him ... he had broken his promise. The memory had replayed and replayed so many times in Azkaban that he couldn't even count how much he'd had to relive it. When he'd tried to convince Hagrid to let him take Harry and Hagrid had refused, telling him that he was taking him to Dumbledore, Sirius had caved in far too quickly.
The hatred for Peter and need for revenge was pumping so hard through his blood that he'd neglected his first priority: Harry. And Peter had taken Sirius's weaknesses, taken them and used them like the rat bastard he was, and Sirius had ended up wasting away in prison for twelve years. He had often thought back on the day he'd found out he was to be godfather, of how he'd promised to go to the depths of Hell itself to protect Harry, and how he had reached that place once he'd set foot in Azkaban, but he wasn't rotting in a cell to protect Harry. He was rotting in a cell because he hadn't been thinking straight and done something stupid, like he'd done so many times in his life before.
And last year, he'd done the exact same thing. Being in the same room with Peter after twelve years had been too much for him. As soon as he'd set eyes on the thing that had ruined his life and murdered the dearest friends he'd ever known, the anger, bitterness, and pure loathing had pulsed through his veins so hard, he swore his blood was singing with it ... the most awful, discordant song imaginable. Thinking back, he knew he had been far from lucid that night when he'd spoken with Harry for the first time the boy could actually remember. Before then, he had no idea that any human body could contain so much negative emotion, even after being around his revolting family for so much of his life.