Me again. After watching PoA, my brain came alive and I was up until 3am, digging out quotes and things from OotP. The fandom has eaten my brain *nodnod*

Yes, I'm still fixating on Regulus being R.A.B.

Let's see what we know about Regulus:

* He's smart - despite what his prejudiced git of a big brother says, why else would Slughorn want "the set"? He was disappointed he didn't get the "talented" Sirius, but was happy with the brother, which says that Regulus must have been nearly as talented.

* He's Slytherin - Therefore, we have cunning and loyalty combined. Unlike Sirius, he was loyal to their parents, though we don't know if he agreed/disagreed with their ideals. We only have Sirius' word on this and Sirius thought Peter Pettigrew was his trusted pal.

* He's the younger son - This meant he was probably trying to prove himself a lot more to his parents. If the Blacks were as old-school as they seem, there was probably a good deal of the "heir and spare" mentality, until Sirius went "Sod you sideways" and left.

* He was a Death Eater - It doesn't say when he joined, but it's clear he's for the pure-blooded society and when it comes to death, destruction and mayhem, he wasn't prepared to go that far.

* He died 15 years before OotP - If I've worked this out correctly, if JKR is being sneakily precise in OotP, he died just after the Prophecy. It'll be about July/August 1995, when Harry's in Grimmauld Place. 15 years earlier was when the Prophecy was made ;)

* He died a few days after skipping out on Voldemort - So, either he was very clumsy or he did something that really didn't go down well with the bossman.

Now, here are my theories on Regulus being R.A.B.

Harry notes in OotP that only Death Eaters refer to Voldemort as 'the Dark Lord'. The note from R.A.B. is addressed to 'The Dark Lord', highlighting that it's one of his trusted minions, though apparently not trusted enough.

Sirius says he doesn't think Regulus was ever important enough to be killed by Voldemort himself, which I concur with. Judging by the note, R.A.B. knew Voldemort wouldn't get him personally, because - if LV came after him - he would be able to read his mind and know he absconded with the trinket. If this was the case, why would R.A.B. bother writing a note to say "I'll be dead when you get this, so nyah nyah!".

He knew Voldemort wouldn't come after him personally. He never joined to be a Voldemort fanboy, so that's why he was probably not very high ranking, unlike his somewhat insane and "OMG VOLDIMORTE R TEH KEWLIES!!1" cousin, Bellatrix. He joined, because of the ideals, not because of the leadership, which probably irritated Voldemort enough to leave him as a low-ranking DE.

Referring back to the fact he was clever and a Slytherin suggests he was cunning enough to keep to the background, learning what he could about his boss and looking for any way he might be able to get out. After all, it's said that a lot of the Pure-blood families agreed with LV until he showed his "true colours" and by then, the DE's involved would know there was no way out unless by death.

This implies, to me, that Regulus knew enough about Voldemort to want out, but didn't know how to do it. After all, he couldn't exactly kill LV, what with all those Horcruxes, which the more observant and dark-magic-knowing DE's probably knew about. And who wants to die for your beliefs, when ti won't make any difference in the long run? So, Regulus has to bide his time a while.

And I see LV being quite smug about the fact that he's immortal. No doubt, a clever witch/wizard/R.A.B. would observe enough to realise what he had done, especially a person raised by dark witches and wizards, like Regulus was. Still, he doesn't think as twistedly as Voldemort does.

Look at the note: the way it's written, it appears that the writer thinks that he has got the only Horcrux. He goes to destroy in hopes that it will make Voldemort mortal. After all, no one save Voldemort has done the Horcrux thing multiple times before, so why should he suspect there are more than 2 or 3 of the things?

So, LV is immortal and R.A.B. knows it's death to try and escape. Until... what's this? A Prophecy stating that someone will be born who will have the power to defeat Voldemort? But... but they won't be able to , because he has his soul divided and there's no way he can die until his Horcrux is destroyed.

R.A.B. has been planning to get out anyway and realises that, if he can get a hold of the horcrux (at least, the one he knows about). So, he heads off, knowing he'll be dead anyway, filtches the little trinket and most likely makes a break for Grimmauld Place to stash it, before running.

My bets say that the locket they find while clearing up, hidden in the precious trinkets cabinet, is the one they need. Regulus probably stashed it amongst all the sentimental crap he knew no one would look at. Plus, it doesn't open anyway, so who would care? (What's the betting that Parseltongue could have something to do with that, eh? :D) And his parents definitely aren't DE's, so they wouldn't be able to get it back to its owner.

So, Regulus tucks it away and legs it, to put distance between himself and it. More than likely cousin Bella comes after him, all crazy and fervent and determined to do her Lord's will, never even pausing to wonder why little cousin is quitting so readily, uncaring of anything.

And so, Regulus dies, without Voldemort ever knowing that Regulus hax0red into his cave, nicked his soul-fragment. I'd love to see the look on Voldemort's face if he found the note. 'Not best pleased' would be a minor understatement.

There was something else, but I can't remember what it is now. Enough to say I've been frantically re-reading bits of OotP and mix-and-matching them with what I now know from HBP.

Yes, my brain has been consumed afresh :)

ETA: Harry catches Mundungus with items stolen from the Black House, including the goblets Sirius chucked out. If he has raided the rubbish, he'll have also found a certain locket which was thrown out.

Who was Mundungus talking to before trying to flee Harry? Wasn't it the barman from the Hog's Head? Ie. Aberforth? Please tell me I'm not wrong about this, because, oh that would be such a perfect way to bring Aberforth in to help! :D