Warnings: A bit of speculation for book 7, so no spoilers really. I'm not expecting the whole thing to be right, but I got a feeling about the identity of the mysterious R.A.B... :3
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If there was one name Remus Lupin thought he would never hear again, it had to be the one the others only knew by the initials: R.A.B. He had kept the secret faithfully all these years - had almost forgotten about it really, as it was just too absurd, too dangerous, to be real. Yet there was the undeniable proof that the plan had actually produced results. For all he knew, it caused his death; the note certainly led him to believe so. But I don't know what to believe anymore, Remus thinks.
The plan had not been his; he was rarely so reckless. The idea had been run by him by one of the most cocksure people he knew in his school days, and he had immediately objected. "It could never work," he had said, "and could hinder attempts by professionals to do the same. Tell the headmaster, if you're so sure of this," he had advised.
His friend had laughed, a hoarse chuckle. "Their way of getting things done never works and you know it. My way may be insane and suicidal, and I'll be damned for eternity as one of them, but all that matters it that it'll get things done. Besides," he added, eyes cold but a trace of a smirk on his face, "think of my family. People'll think I'm evil no matter if I martyred myself for a bunch of babies riding puppies."
"Babies can't ride puppies," was all Remus had been able to say. The other just laughed.
I don't think I can be as brave as you, Remus thinks now. If I say I knew you, were friends with you, all that pent-up suspicion will be free to flow. I wonder if you told me because you knew I'd be damned as one of them, too, no matter what I did...
And what would the point of telling them be, he asked himself, when it won't accomplish anything? So what if you know who found the Horcrux in the first place. It'll just bring me trouble. No one seems too concerned about it. He hesitated, trying to hold back the inevitable "but."
... But... he doesn't deserve to be a villain. And then they'd know they had just one less Horcrux to find and destroy. One less thing to worry about, and one more ally. Or perhaps a new enemy, one who kept secrets that could have changed history, one who knew of the looming threat of Voldemort before he made himself known... and did nothing.
From his seat near the empty fireplace at the Burrow, he could see Harry, and he wondered for a moment if Harry would be as disgusted as the rest of them to know Remus had once secretly befriended a Death Eater, if a traitorous one. After all, it was his word - not very well respected, even in the Order, where some still had problems letting go of old prejudices - against all common knowledge, his word without proof - just some initials that happened to match the ones of his old friend.
You and your family have caused me nothing but pain, he thought, willing his thoughts to be heard, wherever the other was. ... Regulus Augustin Black.
There were many should-haves in his past, and this he believed was one of them. He should have stopped Regulus from becoming a Death Eater and gaining Voldemort's trust. The idea of the Horcrux had fascinated Regulus, who had been quick as a student - perhaps, he thought, as bright as Hermione. He had quickly made up the theory of Voldemort's supposed immortality being related to a Horcrux, maybe many Horcruxes, things he had read about in old documents in his parents' home. Remus had been stupid enough to agree with the possibility, and from there, stopping the elder Black sibling became impossible. Remus didn't even really believe his tales of a dark magic master; at the time, no one had heard of Voldemort except his supporters - which included the Black family.
He never told anyone he had even a passing aquaintance with the Slytherin, especially not Sirius. After mentioning once he had an older brother in Slytherin, the topic became closed to discussion, Sirius prefering to pretend he was an only child. Remus and Regulus communicated through notes left in obscure library books, ones no one but each other would be likely to pick up; their notes would end with directions like, Put next note in How to Brew Your Own Muggle Remedies,or, Place note in Mary Mifflehorn's Guide to Caring for Flobberworm Colonies. They exchanged ideas, strategies, although by the end of Regulus's time at school the notes became increasingly less business related and more friendly. Despite himself, he began to believe that it would work, that one man could enter the Dark Lord's service as a self-employed spy and find the scattered pieces of Voldemort's soul.
Then he never heard from Regulus again. He tried to convince himself it was all a joke. Then he pretended it never happened. Until the false locket was found, it didn't, really. If no one had any memory of an occurrence, did it really even happen?
... I have to tell them. Even if... even if it means they realize all their fears about me were true, it has to be told. If he destroyed it, if he destroyed more... the only one they'll ever know is if they know who he was.
Remus sighed, pinching the bridge of his nose, massaging it. I've been a coward all my life, always hiding from the secrets I keep... Consider this my eulogy for you, Regulus, almost two decades too late. You were a good man, but a terrible Death Eater. This little act of courage is for you.
He stood then, cleared his throat, and asked for everyone's attention.
