Disclaimer: I do not own Harry Potter. It should be fairly obvious, but just in case. I do not own any lines taken from the books either.

Valid Reasons

Dumbledore followed the Auror down to the Ministries' most secure holding cell. Thinking back, it was unforgivable, the way they'd just taken in the boy, despite his dark family history and the secrets he held and told no one, thinking that an eleven year old would not be able to fool the Sorting hat – but he had. They'd not realised how deep the indoctrination and training the dark Pureblood families put their children through was. And the Potters had paid the price.

It had taken many years to capture this man. He was Voldemorts' right hand, the man who had betrayed James and Lily Potter, the man who had murdered their son and his two best friends in cold blood. The child, who tried to feed a school rival to a werewolf, and who, in the last few years, had been right beside Voldemort and his cousin and Lucius Malfoy, maiming, torturing, raping, and killing.

All while laughing. How had they not known?

"He's in here, sir."

The Auror's voice startled Dumbledore out of his thoughts, though he was careful not to show it. The prisoner looked up at the sound the voice. The years in Azkaban had stripped him of his youthful, handsome features, yet there was still a hint of – something. Something in his face drew you in, past the waxy, sunken, alabaster skin, through his eyes. It was the only part of his face even remotely alive.

"Thank you, Auror Biggans."

He whipped his head round at the sound of Dumbledore's voice, glaring with an intensity that made Severus' most fearful death glare seem like a child's petulant disappointment at not getting an ice cream.

Dumbledore sighed as the Aurors forced the man into the restraining chair with the chains on the arms and legs. He didn't wince as they whipped around his limbs, though Albus had seen people scream in pain before from that.

"We'll be within shouting distance," Biggans informed Dumbledore as he and his team left.

Slowly, Albus Dumbledore opened the door and entered the room. It had been designed as an interrogation room and the smell of blood and fear and suffering lingered, echoes of screams of pain hovered on the edge of his hearing. He shuddered slightly. He didn't approve of these methods, but this was war, and they all had to make concessions. Besides, this man was beyond saving, even by his standards. He shoved the guilt away, and with it the memories of the child with bright eyes and a mischievous, cocky grin. It had been false, an act, so flawless that they never realised it wasn't real. Later, in the war, they'd been looking out for people changing, going to the dark side. He'd been there all along. Of course they hadn't noticed a change. The only one to realise that something might not be right was poor Remus Lupin, and he was dead now.

The prisoner schooled his harsh features into a cruel smirk. "Come to kill me, Dumbledore?"

His voice was still slightly rusty, with a rasping edge acquired from the long disuse in Azkaban. Brilliant teeth, obviously repaired after the long mistreatment they'd undergone, were a reminder of the boy.

He wasn't evil in the way Tom was. With Tom you knew where you stood.

This man gained your trust and stabbed you in the back.

"There will be no killing tonight." Dumbledore replied placidly, knowing that even as he spoke, the man's comrades roamed the country, searching out their next victims. Evidently the man knew that two, as a spark of sick humour lit in his eyes.

"No, I suppose not," he remarked flippantly. "You never had the guts for killing, did you? You always let others do your dirty work while you looked away, and if anything went wrong, you threw them away like the pawns they are, letting them take all the blame, secure in your delusion that you know everything."

What an odd choice of words. Then again, the man was mad.

"I came to ask you why you joined the Death Eaters."

The man's eyes narrowed slightly. "Congratulations," he mocked, leaning back in his chair as though it were a throne, regardless of the chains. "You finally decided to question me." Abruptly, his face twisted with fury. "After all, it's only two fucking decades too late!"

Albus waited, raising an eyebrow. The man matched his expression, all trace of his anger gone in an instant.

They sat there facing each other for a long time. He'd always been strong willed. Albus had seen that from the start. It was part of why they had believed his act of the rebel.

Albus broke the silence, after it became clear the man was never going to crack from that method. "So, why did you?"

Still he was silent, until Albus wondered if he was ever going to answer.

"I suppose you never figured it out."

He didn't sound like a madman. If anything, he was too sane, dangerously sane.

"Figured what out?"

There was another long pause. Dumbledore waited patiently.

"Figured out that you were wrong."

Dumbledore's eyes and voice hardened. "We know you were acting right from the start. We were wrong about that, thinking that you were genuine. Thinking you were on our side."

The man actually seemed startled for a moment. "Right from the start – that explains a lot of the comments your people have made to me over the years." He laughed; sending a chill down Albus' spine, even though he knew, logically, the man could not hurt him. That laugh was the last thing many people heard, and what countless others heard as they were held under the Cruciatus. "You're wrong – again."

Dumbledore felt a frown cross his forehead. He would have legilimised the man long before now, but for the fact that the man's occlumency shields surpassed Severus's and rivalled his own.

The man continued. "You still don't get it. I joined the Dark Lord because no one believed my innocence."

Dumbledore had to hold back an extremely non-omniscient snort. "We all believed your act. You know that."

"No, I don't." The man leaned forward, eyes burning with a frightening intensity. "It wasn't an act."

Dumbledore was appalled at the Death Eater's sheer audacity. For him to say that, to deny what they both knew was the truth...

"You are contradicting yourself." He spoke quietly. "Only moments ago, you admitted to being a Death Eater. To say that your act was not an act would mean that you were not a Death Eater."

Another silence fell.

He'd had such high hopes for the boy. He was prodigious at Defence Against the Dark Arts in his schooldays, and had an instinctual grasp of all magic.

Maybe they just hadn't wanted to see, had been so terrified by the thought of him turning Dark that they'd missed the signs saying he already was.

Seeing this man was reopening old wounds.

"Wrong again." The prisoner's voice dragged Dumbledore back to the present, where a spy and traitor sat chained across from him. "You see what you want to see. When I was thrown in Azkaban you decided, in your own mind, that I was guilty. Once your mind was made up, nothing would convince you otherwise. Your belief tainted your memories of me, made it seem like I was guilty. Look back in your pensieve. Did you ever see the fidelus charm performed? Did you not think to realise that the handwriting on the note that I delivered to you, detailing the Potters address, was not my own?"

"What are you saying?" Dumbledore also now leaned forward, frowning in earnest.

"That you were wrong."

A bitter, barking laugh echoed off of the walls of the cell.

"That is not an answer."

"I already gave you my answer. You just chose not to listen." He tossed the long, tangled ebony hair out of his eyes, and Dumbledore once again saw the laughing boy, the child they'd trusted.

"Very well, I shall take my leave." Dumbledore stood. The prisoner grinned.

"Just remember, old man. Remember what I said."

Dumbledore swept out of the room, Sirius Black's parting words echoing hoarsely behind him.

"You were wrong."

Seven years earlier.

"Did you hear me?" Ron said weakly, though he was clinging painfully to Harry to stay upright. "You'll have to kill all three of us!"

"Of course. Avada Kedavra! Avada Kedavra! Avada Kedavra!"

They didn't stand a chance, as three killing curses hit their targets from behind.

Sirius's face twisted. "Peter!"

Peter grinned wildly, his eyes showing a manic, panicked energy. They heard footsteps running up the stairs.

"You're dead, traitor! Avada Kedavra!"

Peter dodged and turned into a rat, running for the door –

-only to be stepped on and killed accidentally as Remus Lupin sprinted in, eyes wide in panic, evidently having heard Sirius's last few words...

Six and a half years earlier.

None of his letters had been answered. He knew from the tracking charms he'd placed on them that they had all been destroyed, and after the first one they hadn't bothered to even open them.

Another year. None of them believed him.

Of course not. After all, the great Albus Dumbledore said he was guilty, so it must be true.

He was hiding out in Albania. He'd heard from his parents, oh-so-long-ago that it was the perfect place to hide things, the perfect place to hide yourself if you were on the run.

He wanted revenge. Dumbledore and his righteousness, his greater good, his bloody Light-sided followers...the whole lot of them. He had no ties to them anymore. James was dead. Lily was dead. Remus was dead. Peter was dead, not that he was much of a tie to the light any more. Dumbledore and anyone who he had ever considered a friend had betrayed him. The ministry of magic – an utter joke! They'd never even heard of justice. He had his own justice. Peter was dead, at Remus' hand, or rather, foot. And the irony was that he hadn't even known.

He kept walking, the anger reaching boiling point. The rage. The betrayal. The bitterness.

He heard someone coming. Boots crunching the dead leaves.

Changing smoothly into the huge Grim that was his animagus – and it actually was a Grim, contrary to the beliefs of anyone he'd told, which wasn't many, none of who were still alive – he shook himself out of his thoughts, slithering forwards on silent paws to look.

A muggle. Alone. Walking through the forest.

Sirius Black grinned viciously. Finally someone he could force to feel his pain. He turned back into a human.

"Why, hallo there. What are you doing out here?"

The man spun, and then backed away from Sirius. "Who are you!" he yelled in fear. Judging him on only his appearance. How shallow. How would he like to be judged for something he could not help, say, being a muggle?

Sirius could feel the anger rising up inside him again. Boiling, spilling over, and destroying anything that happened to be around. "Oh, no one important," he smirked, feeling the darkness of Azkaban beam out of his dark eyes. "Just...Death"

It was then he renounced the proclamation he'd made twenty years ago, as he fought his way out of Grimmund Place, to never use the Dark Arts.

Wandless, he pointed a pale, dirty hand at the muggle.

"Crucio."

The screams echoed through forest for long hours after that, accompanied by maddened, bitter, reckless laughter.

So that was why Bellatrix loved that curse so much.

Six years ago.

Black watched as Voldemort rose out of the cauldron, vicious glee filling him. It was done. He'd brought back the nightmare of every Light wizard. Who better to wreak destruction and havoc?

He'd thought long and hard about his revenge. He wouldn't be able to get it himself; if it got out that he was targeting Dumbledore the entire Auror squad would be on his back. He wouldn't be able to do anything; he'd be hard-pressed to even survive. He needed something widespread, on the scale of Voldemort's last reign of terror...and that was when he'd realised. What the nightmare of every Light wizard was.

Voldemort's return.

So he'd set out to aid that. His Dark upbringing had been immensely useful – he almost shuddered at the memory of Voldemort's suggestion for a potion. Thankfully he'd known of a better option. He didn't really fancy losing any body parts, though he would have done it anyway if there hadn't been another option.

"My wand, Sirius."

Bowing respectfully, Black handed Voldemort his yew and phoenix feather wand.

"Your arm."

Sirius felt a thrill of something run through him. Fear? Excitement? Anticipation? All three?

He held out his left arm, pulling the ragged sleeve up the reveal his bare skin. Voldemort pressed the tip of the wand to his skin and muttered a few sentences of Latin before pausing and uttering the final word. Morsmordre.

He felt it burning on his arm. The Dark mark. Fitting, for a Dark Wizard.

Triumph.

Take that, Dumbledore.

Present day.

Sirius Black laughed as Dumbledore departed. He wondered if the old man would ever figure it out. Probably not.

An accusing confession, told to one who had closed their ears and eyes. That interrogation room was retired shortly afterwards, as whenever someone entered, the conversation between the betrayed and the betrayer would start playing out in whispered voices. No one ever figured out how, and it was donated to the Department of Mysteries, where the Unspeakables labelled it as an anomaly of magic.

It became the Unspeakables private war memorial. And still the conversation plays. That fatal line is whispered over and over.

"You still don't get it. I joined the Dark Lord because no one believed my innocence."

And still, no one understands.

A.N. edited so the small section from the third book was reduced to one lines worth. And could someone please tell me what they think of it? It's easy enough, there's a button labelled "review" right there…

A.N. edited again to fix some minor grammar and font issues, and to remove the poem. Again, please review.