HBP SPOILER The Dark Mark glinting on his arm, Regulus Black knows he can't escape from Voldemort's claws forever but it's just too late to right the wrong. And now the least he could do is to make his death worthy and Sirius proud. R.A.B. Theory

Note: This story will follow the chronology of Regulus's last week alive, but the dates were made up.

- WARNING: GRADUAL HBP SPOILER -

Regulus Alphard Black

25 July, 1979

It was no ordinary night like others. Although it was mid-summer, everyone, magical or non-magical, could feel the chill in the air. And the sky was of a dull, velvety black, with the only source of light coming from the moon. Perhaps a few Dark Mark were hovering somewhere in the country, illuminating the sky, but Regulus Black wouldn't know. He had too much going on in his mind to care about other people's business.

Standing among a dozen or so figures in the outskirts of Britain, Regulus was taking a prominent position in the circle they physically formed. Like all his fellows, he was both hooded and masked, wearing a long, lucrative black cloak that swept past his knees. One could not tell their individual identities, except that their appearances alone could distinguish them as the Death Eaters, the most feared men second only to Lord Voldemort the Master himself.

"… The Dark Lord wishes that all the tasks would be accomplished before the break of dawn," Lucius was saying quietly, his lips barely parting, but the men have no difficulty hearing him, given the deadly environment they were standing in. The men inclined their heads, showing their understanding. "We will then have an audience with him in the castle, where we will be given directions as to what to do next –"

Lucius stopped hastily, eyeing the bush that wavered for a moment before it was back in place, and he turned very still. His silver eyes were darting calmly back and forth around the place until – "RUN! THEY'RE HERE!" he yelled.

All at once, the men shattered from the circle, Regulus was among those swiftest in movement. To his credit, Lucius sprung forward, shielding all others from the Aurors that materialised behind the bushes. Grasping his wand tightly in his hand, Regulus ran towards the forest, he could hear a man was tailing him.

"Stupefy!" Regulus bellowed, pointing his wand behind him without turning. Judging from the sound of it, the spell didn't hit the Auror, but the Auror had stumbled sideward in the dark trying to duck it.

"STAY WHERE YOU'RE!" Another Auror shouted, some hundred meters away from him.

Still running, Regulus chanced a glance over his shoulder, a belligerent smirk lurking on his young, boyish face. Yeah, like I'd really listen to you and stay, he thought sardonically as he disappeared into the woods.

Once deep into the forest, he tried to disapparate. However, he couldn't; some Auror must have performed the Anti-Disapparition charm to the area. Feeling stupid but having no other alternatives, he kept running, squinting at his left and right every now and then. About a hundred meters away from him, Regulus could scarcely register the silhouette of someone running straight ahead. He looked up at the face of the man at the same moment as the man glanced over, their eyes met and Regulus saw he was wearing a white mask identical to his. They nodded at each other as a sign of acknowledgement, then turned, each taking a detour that broadened their distance.

About ten minutes later, Regulus turned again at the seventh junction he reached, he was barely running now. As far as he was concerned, the field was quite clear, and he was exhausted, he could feel his legs beginning to give way. He whirled around, stepping backward slowly as he did so, his eyes sweeping over the whole place with caution. He tried again to disapparate but, much to his dismay, to no avail. Damn the authoritative Anti-Disapparition spell, he cursed under his breaths, it was always so comprehensive.

Breathing hard, Regulus backed against the nearest trunk and slid down until he could rest on the root. He pulled back his hood and reached for his mask, intending to pull it away, but decided to leave it on at a second thought. He ran his fingers in his dark hair roughly, which was soaked in sweat, waiting for his quickened heartbeats to slow down. He could tell the excitement from attending the Death Eater meeting hadn't quite faded. But the smile on his face faltered as his mind raced back to the missions discussed.

Although Regulus had joined the Death Eaters for almost 3 months now, he had only been to a few meetings, majority of which were headed by his cousin-by-marriage, Lucius Malfoy, leader of his 'division'. Tonight's was the seventh, but it was the first time Regulus had been asked to join in the next torturing while at most other times he was only ordered to spy on someone. Perhaps he should be delighted, as the participation would be considered a status symbol; however, the mere thought of actually torturing someone gave him the creeps. He knew it. He knew he was not ready to torture.

The Imperius Curse he could muster flawlessly, but he still had mild difficulty performing the Cruciatus Curse to achieve its full effect, let alone the Avada Kedavra. He attributed the failure not to talent or intelligence, but doubt. Doubtfulness of whether what he was doing was the right thing to do. It was peculiar that he had such perception, because Slytherins never had doubts. They talked of many things. Awareness, ideologies, yes. Morality and conscience, more often than not, but it meant nothing, as their interpretation of it was nothing more than a full set of racist indoctrination. But the Snakes never questioned the rationale behind the pureblood mania nor were they ever uncertain of the justification of their belief.

Regulus leaned back on the trunk and closed his eyes, suddenly remembering it wouldn't be the first time he tortured. He could still recall in detail the night when he had got the Dark Mark stamped on his left forearm…

Lord Voldemort had been seated in a throne-like chair, with all the masked Death Eaters lined up on either side of him, and numerous Death Eater wannabes gathered at the very centre of the hall. They were waiting anxiously for the ritual to begin when two Death Eaters dragged an unkempt woman out from no where. There was muteness when all eyes in the room were focused on the unconscious form abandoned on the marble floor; Regulus suspected he had got a grasp of what's going to take place.

"Show me your strength through granting this Muggle woman what she deserves," Lord Voldemort had stood up and said in his frosty voice, his blood red eyes narrowing into slits dispassionately. "Prove to me each and every of you is worthy of the trust and confidence I shall place on you." He flicked his wand at the woman and regained dominance of his throne.

The woman's eyes flipped open immediately and she became conscious again for the last time in her life. She seemed to comprehend in a split second what was going to happen to her, but she was calmer than any woman could be; she pleaded, although her face showed nothing other than desperation and hopelessness. "Please, have mercy… Spare me… Please –"

But then a cruel word cut her begging. "Crucio!"

All at once, the woman fell backward onto the cold floor, twisting like mad, rocking back and forth and screaming hysterically. Regulus looked up in surprise; a fellow Death Eater wannabe had already raised his wand and begun proving himself worthy enough to deserve the Dark Mark. Those around Regulus followed suit.

The woman's screaming intensified and reverberated in the spacious chamber. Feeling the Dark Lord's eyes on him, Regulus quickly put on a face rid of emotions and pointed his wand at the poor muggle. He felt a lump in his throat as he uttered the word, "Crucio!"

The woman shrieked some more, her petite body now quivering so vigorously it was as if she was continually struck by a strong lightning, and her face was almost distorting.

Regulus couldn't bear to witness it anymore. He closed his eyes as though in concentration when he uttered the Cruciatus Curse again. The chill remained in his spine, although he no longer saw the deforming figure. Ten or so Cruciatus Curse performed on her simultaneously, the agony and excruciation in the woman's screech were more pronounced than ever, and mingled with this was the occasional recognisable sound of sobs. Her cries grew consistently louder by every second, and after a long period, it stopped.

Regulus opened his eyes to discover the woman no longer yelling, though her body was still twisting on the floor. Her eyes were open, but they didn't blink anymore.

The killing curse not yet used, the Muggle was tormented to death.

Lord Voldemort rose from the chair with a sneer, but Regulus couldn't register what he said afterwards… An hour later, Regulus emerged from the castle with a grey skull on his left forearm, his innocence lost forever.

Since that night, the woman's scream sometimes haunted him at night, but Regulus always managed to free himself from guilt as he reminded himself she was a Muggle – whose race had always despised the magical folks just because they didn't possess the gift themselves.

Regulus ran a hand over his face and wiped the sweat from the back of his neck. He could already feel the burden of uprooting the Bones family starting to sink in. Torturing Muggles was one thing, killing purebloods was another. As far as he knew, Edgar Bones was almost as much of a pureblood as he was, and Regulus wouldn't be surprised if their family trees had intersected at one point. He took a deep breath, the same time tomorrow night; he would probably be overwhelmed with nausea, vomiting somewhere in a back alley. Perhaps these things need a bit of getting used to, he made a mental note.

Abruptly, Regulus thought he heard some rustling of cloak behind him. It put him instantaneously on alert. With the quietest movement he could manage, he pulled his hood over his head, straightened up and hid his entire body behind the trunk he had been leaning on, clutching his wand firmly.

For a moment, he strained to listen to the faint sound, pressing his ear hard to the wood, but he heard nothing. There was neither sound of receding steps nor that of advancement. It seemed the intruder had stopped walking. A few silent seconds passed before Regulus cautiously peered from where he was.

In the very heart of the forest where moonlight was completely blocked away by the trees, the lit wand provided Regulus with no problem as to where to focus his attention on. He observed his advancer. Even though the man had his back to him, Regulus could easily recognise him.

Tall and athletic built, his dark hair a rare shade of blue and black, and almost haughty in his demeanour, the man moved with a sort of aristocratic aura that Regulus could remember admiring and envying like forever. The man was called Sirius, with the surname of Black.

Regulus's eyes lingered on his elder brother, from whom he had estranged for some years now, then a surge of nostalgia struck him, nonetheless, he tightened his grip on his wand unconsciously.

Sirius was turning slowly, searching for life under his lit wand. Regulus quickly hid behind the trunk again, his heart racing, the last thing he wanted was to be discovered by Sirius in a spot where the Death Eaters had had a meeting not long ago. Within seconds, the jet of wand light was cast upon the tree behind which Regulus stood. Lucky that the trunk was so thick, he could conclude from the shadow that not a hint of his existence was given away.

There was a hesitation, then Regulus heard the echoes of Sirius's steps fading away and the forest fell silent again. He gave a relieved sigh. He waited for a few seconds before he emerged from his hiding place, thinking it's about time to continue his flight. But before he could take another step –

"Expelliarmus!"

His wand jerked out of his hand and Regulus stared at it when it landed some ten meters to his right. He didn't make a dive for it; instead he just stood on the spot unflinchingly then turned to face the Auror.

They stared at each other. Still having his face veiled, Regulus wondered if his brother knew who he was looking at. There was really no telling from reading Sirius's expression, but when their grey eyes met, the dangerous glint in Sirius's telegraphed a clear message to him: Sirius recognised him.

"Had a nice meeting discussing who to kill next, Regulus?" said Sirius, glaring at him.

"Best meeting yet," Regulus answered, also glaring.

He couldn't tell what his brother was thinking about, this time not due to Sirius's impenetrable countenance but because it was changing too quickly. It expressed almost at the same time various emotions, delicate and quick-transforming as the clouds on a thunderous night, chased one another continually over his shadowed eyes. Recognition, shock, betrayal, fury, hatred… and worse still, the one emotion that appeared oddly foreign to Sirius's face – disappointment, which was also the one emotion Regulus detested seeing the most.

Though he was by no standard hypocritical, Regulus always sought to satisfy and appease the ones he respected. And Regulus had always hated disappointing people or failing to meet expectations laid on him by others. Sirius should know that.

But there he was, his look was making the muteness even more unbearable. Regulus didn't look away from him; it was as if he was transfixed that he couldn't. Oblivious though he was, Sirius still had that power over him, he had that power over everyone, which called forth a boundless confidence in him and tempted people to rely on him. There was a time when Regulus was glad that he had someone to rely on, but now, he wasn't sure anymore.

Regulus was staring from the balcony that linked their bedrooms together when Sirius threw his stuffs into the trunk on his bed, muttering under his breaths indignantly. He was sure Sirius had glimpsed him when he walked into his bedroom, but he obviously wasn't in the mood of acknowledgements. From what Regulus could gather from eavesdropping on the fierce conversation that had taken place in his parents' study, their parents were demanding that Sirius should join the Death Eaters once he graduated from Hogwarts but Sirius rejected and wouldn't compromise. Sirius had then strode out from them, slamming the door behind him and rushed upstairs to pack his belongings, seemingly entertaining the idea of running away.

Regulus had regarded the gesture as a menace against his parents' proposal and indeed, Sirius showed no intention of leaving at that night when they shared a rare bedtime chat in the balcony. They had discussed a lot of things out there, the news, people, life in general, Hogwarts, philosophies… and some random stuffs but they were both careful not to mention things that might trigger any conflicts.

"You know what?" Regulus had said when they eventually drifted off to separate musings, "Sometimes I tend to think you're manipulating me."

Sirius looked at him. "Really? Why am I unaware of doing so?"

"That's the problem, Sirius. You do not intend to do so, but that's exactly what you're doing."

Sirius sipped the luxurious red wine he had taken from his parents' cupboard tranquilly. "And I've got the impression that you don't mind," he said.

"Well," said Regulus thoughtfully, "if I must be manipulated, it'd better be by you than anyone else."

"Why?" Sirius looked almost in alarm.

"Because as much as I hate to admit it, you're always right."

"I'm not always right, Regulus. But you can assume whatever advice I give you would be what I consider to be best for you." Sirius had smiled then, but it was an odd smile, somehow it looked forced. And Regulus thought he had caught a glimpse of misery and apprehension in Sirius's eyes before he looked away.

When Regulus awoke on the next morning, Sirius had left the house, his room completely deserted. He had left Regulus a letter, the content of which Regulus could no longer remember, because he had torn it up in agitation before reading it.

From that day on, they had not uttered a single word to each other, not even when they met again at Hogwarts. When Sirius graduated a year later, with the news of him being accepted by the Auror Department with early decision circulating throughout the school, Regulus finally appreciated that he had lost his brother for good and he had sworn never again in his life would he resort to rely on Sirius.

Regulus's stare turned into a glower at the man before him, the man who had walked out on him four years ago. He tried to seek in Sirius's face whatever it was that had once fascinated him for so long, sarcastically he found none. He almost brought himself to sneer… but stopped dead when the blazing badge carved in the front of Sirius's cloak captured his attention.

The Auror badge.

The Auror job, Regulus knew, had always been Sirius's aspiration, albeit his parents and entire family held no courtesy towards it and had been less impressed by the occupation than most others. Regulus could remember his parents persistently discouraging Sirius in an accidentally-on-purpose way, but on the contrary, Sirius's enthusiasm in becoming an Auror had never lessened. And that's what Sirius was now, a rising talent in the Department of Magical Enforcement.

His eyes fixed on the prestigious badge on Sirius's chest again, Regulus suddenly felt a pang of jealousy as it occurred to him for the first time, that he and his brother were now both warriors, except of course Sirius was fighting to save, something he was undoubtedly proud of doing, while Regulus was battling to destroy, without knowing why he should.

Both born in the Black family, why did Sirius always manage to act his own way while Regulus was always enslaved?

Glaring at Sirius's immaculate face, Regulus had an urge to tell him it was only after he left that their parents turned to the younger son, hoping the last heir wouldn't fail them – to right all the wrongs and to fulfil what the elder son didn't. But Regulus stopped himself just in time, he wouldn't bring himself to admit that he was burdened by his Death Eater façade.

"Do you know what you're doing?" said Sirius at long last; his voice deadpan and his eyes betrayed no feelings.

"I rather think that's my business."

"Perhaps it is. But you know what? You've become an eyesore for everyone," Sirius commented coldly. "The mask you're wearing doesn't even suit you."

"I disagree. I feel quite comfortable under it."

"You do, do you? Tell me, do you feel safer beneath it?"

Greatly infuriated, Regulus ripped the mask away from his face violently on the spur of the moment and threw it onto the wet ground, his breaths becoming heavy. He took a large step towards his brother, clenching his fists into balls. He almost spat at him. "Stop pretending as if you know me well, Sirius, because you don't. What I am capable of doing now might surprise you more than you can imagine."

"Oh, really?" Sirius hissed, taking a step nearer too. "You have to admit it. Nobody on this earth understands you more than I do. And it occurs to me you're just cutting your own throat."

His knuckles white, Regulus was quivering in anger from head to toe and he glared at Sirius more intensely. At that moment, he wanted nothing more than to raise his hand and smacked Sirius right in the face, but it was as though he was held back by invisible strings that he couldn't even move. Sirius seemed to have noticed this, and he stared back sharply as though daring him to make the first move.

Now that they were both bare-faced, the exquisite resemblance in appearances became very emphatically announced. The same dark hair, the same grey eyes, they looked so much alike, but curiously, the field issued from their individual beings were of a completely different story – they repelled each other and fought to gain dominance.

For a long time, the Black brothers glared at each other more hostilely than ever. They didn't break the eye contact until someone's voice slashed it.

"Sirius?" James Potter was striding at a long distance from them, his lit wand pointing at their way but obviously he couldn't see them clearly. "Caught any?"

Sirius's eyes darted back to Regulus and narrowed, before he called back, "None. We should go search the other way." He turned and walked away to meet Potter, but not before he had lifted the Anti-Disapparition spell cast on the area.

Regulus was still glaring maliciously as Sirius's silhouette became smaller and smaller until it merged with the darkness.

But on that night, he kept tossing and turning in his bed, pondering over what Sirius had said.

What was Regulus Black doing again?

He's cutting his own throat.

A/N: Like it? Hate it? Well, I must admit I am not sure if R.A.B. really stands for Regulus A. Black, so far this theory lacks empirical evidence except if you consider the initials, but I really really hope Regulus is the one who destroyed the Horcrux. And being a devoted Sirius's fan, I can't help bringing Sirius into the picture. Sorry if my obsession irritates. (I wouldn't mind if you call me 'Sirius's girl through and through', hehe)

And thanks Makosh, (I was too exhausted to have noticed the possibility that Regulus is RAB when I finished reading HBP, it wasn't until I read your review that I could bridge the two persons together. THANKS for inspiring me!) As usual, Pleasereview! Tell me what you think of it. P.S. Have a nice Harry Potter Birthday!