Almost a week had passed before Regulus was summoned by the Dark Lord. At that point he almost didn't care what happened, as long as he didn't have to walk around with a sense of impending doom anymore. In one way or another, things would be settled tonight.

As he arrived at a grey nondescript house which served as tonight's meeting place, a small sigh of relief escaped him; many other black robed figures were moving around the building. If Voldemort were to kill him for knowing his secret, he probably wouldn't do so in front of the others.

That didn't mean he was completely out of the woods, he was not sure he could get away with outright lying to his Master, Occlumency notwithstanding. He silently prayed it wouldn't come to that as he entered a large room, where the Dark Lord resided in a throne-like chair.

The meeting followed the usual routine; Voldemort started it with a passionate speech about why the Mudbloods should be wiped out of existence and how the Purebloods would reign supreme once this was done.

It was nothing he hadn't said before, but judging from the enthusiasm from some of the other Death Eaters, it might as well have been, most of them clung to his every word, their expressions ecstatic. Regulus refrained from rolling his eyes; that certainly wouldn't help him blend in with the crowd.

Not that anyone was likely to recognise him with his mask and cloak, though the Dark Lord had an unfortunate habit of calling his followers by name that Regulus wasn't too happy about. He thought it rather defeated the purpose of wearing masks in the first place. As the speech was concluded Voldemort did, indeed, call upon them using their given name.

A few Death Eaters at a time went to him to rapport the progress being made in their various assignments, and receiving further instructions. As Death Eater by Death Eater was called upon by the Dark Lord to then silently leave the building, Regulus became more and more nervous.

The room was almost empty when he finally beckoned Regulus, who crossed the creaky hardwood floor in a brisk pace to kneel at his Masters feet "My Lord" He kissed the hem of Voldemorts dark robe, just as the others had.

"I was pleased by your elf's assistance" Voldemort said, almost casually.

Regulus blinked in surprise, it was uncommon for Voldemort to make small talk, especially about something as trivial as elves. The uneasiness escalated and he felt as if he had accidentally swallowed a whole herd of Hippogriffs, that were now trying to claw their way back out to freedom.

"I'm glad" he stated vaguely.

The Dark Lord eyed him intensely and Regulus quickly coated his mental barriers with memories of their last meeting, as well as the joy he had felt at pleasing the Lord when he first met him all those years ago. The moment passed and Voldemort leaned back in his chair again, reassured of Regulus devotion.

"Bellatrix told me you haven't spoken to your blood traitor brother for almost three years"

The sudden change of subject left Regulus somewhat confused, but he quickly composed himself.

"Yes, I do not want my reputation ruined by his unworthy presence"

Voldemort eyed him thoughtfully for a while, his expression unreadable.

"Is it possible to repair your relation?" The Dark Lord said it in a casual way, but his intense stare somehow belied this.

Regulus carefully weighed his options, he considered his relationship with Sirius as beyond all repair, but how to convey this without being exposed to the Cruciatus Curse?

"I could try, but I doubt the blood traitor will ever trust me again"

Voldemort frowned at this and Regulus tensed his muscles in case of an incoming curse. "That is unfortunate..." he seemed to reach a conclusion as to whether the disappointment was worthy of punishment, "Never mind, I will find information some other way"

With this the Dark Lord absent-mindedly waved him a dismissal and Regulus hurried out, seething with anger.

How dare he even ask that, as if I would ever spy on my own family – estranged or not!

He apparated back to the house and continued his infuriated ranting there, pacing back and forth in his room.

This really was the last straw, Regulus was now certain he had made a foolish mistake by joining the Death Eaters, though there wasn´t all that much he could do about it; quitting was a sure way to get killed and refusal to participate in raids was bound to end the same way.

Suddenly he stopped pacing, an evil smirk slowly spreading across his face:

If it´s a spy Voldemort wants, then a spy he will get.

He quickly summoned quill and parchment and wrote down the location of a prison camp, along with information on guard duties and wards.

Dumbledore would probably distrust this first note, thinking it a trap, but the next one would probably be more trusted, once this one´s information was validated – at least if he kept the same signature.

He stroked the end of the quill against his cheek as he thought – an old habit of his, then chuckled in delight. Regulus was an old family name and meant Prince or Little King, but the star was also known as Cor Leonis which translated to heart of the lion – the name seemed fitting for so many reasons.

With a flourish he signed the letter "Lionheart" and sent their other house elf – Mitty – to the post office in Diagon Alley, it wouldn´t do to have their family owl recognised by the receiver.

He sat down at his desk to think of other important information he could relay to the Light side.

After only a couple of minutes his burning resolve gave way for cold uncertainty; this must have been his single-handedly most Gryffindor moment, and by that he didn't mean brave and valiant – rather foolish and reckless.

In the heat of the moment he had cast caution aside and without any thought of the consequences, should he be caught, betrayed the most evil and powerful wizard in Britain. He hid his face in his hands as cold terror gripped him and no further planning was done that night.

Three days later there was a summon from an irate Lord who in cold fury told them that the enemy had taken over one of the safe houses, freeing six important prisoners in the process. As a result all prisoners now would be double-checked for tracking spells.

Since all four of the Death Eaters who had been there in the fight had been captured or killed he took out his displeasure on some of the low ranking Death Eaters who didn't look contrite enough.

After the unfair punishment the Dark Lord's mood seemed to have been improved some, and one of his usual speeches ensued – ending with the announcement that a raid on Diagon Alley would serve as retaliation. The attack was planned to be executed in four days time at noon.

Back at Grimmauld, Regulus sat down by his desk, and started writing Lionheart's second note to Albus Dumbledore. It would be much safer to stop sending notes, but his conscience wouldn't let him back out now.

The days between the first note and the summon had been spent planning how to remain undiscovered. After jotting down the general details and a plea to not make it look like they had been tipped off, lest he be discovered, he sent Kreacher to post it the muggleborn way – since Hogwarts had a special way for the muggleborn parents to contact their children.

A few seconds compulsion of a muggleborn witch was all it had took for him to gain that information, and he was rather pleased with himself for it – there was no way to see exactly where the letter was posted from.

The day of the raid Regulus was extremely nervous; he had basically set himself up as a target for lethal curses, but it was too late to back out now. He donned his Death Eater robes and an old family heirloom – a ring that also worked as a powerful portkey, voice-activated and able to penetrate most anti-portkey wards.

He apparated to the gathering site and made sure he stood in the middle of the clung of Death Eaters joining the attack to have a human shield around him.

As soon as he appeared in the alley he cast a Bombarda at one of the shop windows, he followed up an Incendio at some barrels in a corner – refusing to cast anything at an innocent bystander, but unable to just stand around and watch.

Pops around him heralded the arrival of order members and Regulus started to inconspicuously sending stunning spells at unsuspecting Death Eaters, he was close enough for them to not notice from whom the spell was cast.

A short distance away he spotted his brother and Potter, fighting side by side and doing a fine job of it. Quelling a pang of jealousy that Potter had taken his place as Sirius' brother in all but name, he decided to portkey home before the deadly duo got him – it would be utterly ironic if his brother killed him now that he had actually switched sides.

The loud crack of Aurors appearing confirmed his decision as a good one. With the words "Toujours Pur" the alley disappeared and his father's study in Grimmauld place appeared. No one was there so Regulus unrobed and snuck into his room to calm down before the inevitable "You-failed-and-must-be-punished" summon. He shuddered at the thought – it was bound to be unpleasant.

He distracted his mind from conjuring up unwanted speculations by writing a list of everyone he knew was a Death Eater, along with people he suspected but hadn't yet confirmed.

As he read the list he noticed one name missing, he was sorely tempted to leave it out, as if that simple act would make it so. With a sigh he wrote "Regulus Black" high on the list of confirmed names – he could just imagine his brother's disappointment.

When the summon came minutes later, he gave the note to Kreacher, Voldemort was irrational when it came to punishments - more than one follower had been punished to death by their Master – but even if Regulus got killed today in a fit of rage, the truth would be known; most of it anyway.

He turned to leave but changed his mind at the last second "Kreacher", the elf popped into the room "Yes, young Master?" Regulus hesitated for a second, then softly said "If I die, I want Sirius to know I'm Lionheart, could you do that for me?"

Kreacher's eyes widened at the mention of Regulus dying, but he nodded somberly "Yes Master, Kreacher promise"

Feeling strangely reassured at the thought of his brother knowing that he had changed, that he wasn't a horrible person through and through, he left for the meeting.

It turned out he needn't have worried about getting killed that day, the Dark Lord was furious, oh yes – his rage was quite something to behold – but he blamed the lower ranks for the failure. It made absolutely no sense whatsoever, not that Regulus complained.

And so his little game continued; supplying Dumbledore with enough details to do a lot of damage without revealing so much that it was obvious there was a spy. Being a Slytherin to the core Regulus would have enjoyed it immensely, had the stakes not been so high.

Another definite mood dampener was the death of his father, Orion Black, that summer. Dragon Pox had taken him after some time's sickness, and though Regulus had never been close to the man, he still missed him.

Though Sirius had never been properly disowned, it was Regulus who got the dubious honour of managing the Black finances.

A very pleased Dark Lord summoned him the day the decision was made; to congratulate him of course. Though Regulus caught the not so hidden implication that now the Blacks could donate even more money the cause.

Back at home, there was a certain part of their conversation that was repeating itself in Regulus head over and over again. Voldemort had actually chuckled as he told him "Do you know your brother was hoping to be in charge of your family's' part of the Black fortune?", at Regulus polite shake of the head he continued with malicious glee "he was hoping to stop money from the Black vaults funding our side, apparently he wrecked his entire bedroom when he found out"

Regulus had forced his expression into a condescending smirk "As if we would ever let a blood traitor take charge of anything". The Dark Lord had jovially agreed.

It was quite obvious there was a spy among the light side; someone close enough to Sirius to know about his bedroom, the thought of the danger his brother unknowingly was in made him shudder. As soon as he had returned he had sat down and tried to figure out who the spy could be.

The answer was quite obvious, and he wrote a quick note from Lionheart, this one addressed to Sirius, he didn't care that breaking the pattern was risky – his brother needed to know immediately.

'There is a spy amongst you; he seems to know a lot about you Mr Black. Are you sure the wolf is tame?

/Lionheart'

Severus had told him all about Lupin's attack and Dumbledore's unfair treatment after it, Regulus had sympathised with his friend wholeheartedly; a dangerous half beast had no place in a school, or the world for that matter, in fact it would be better for all persons involved if they were all put down.

Despite their status as less than human, Voldemort had recruited many monsters for his army, and Lupin switching sides for sweet promises of better treatment and perhaps even a cure was not that hard to imagine.


Only a couple of weeks later Voldemort summoned his followers, furious. They were called upon one by one to chat with their Master behind a silencing charm.

When it was his turn, the Dark Lord didn't even greet him "It has come to my attention that there is a spy in my ranks" Regulus fought down the panic; it seemed like today would be the ultimate test on his occlumency shields.

"Any idea whom it is my Lord?" he kept his voice even, with a trace of anger suitable for a loyal Death Eater to have at the thought of betrayal. He let pictures of other followers flicker through his mind.

"Apparently some fool who calls himself Lionheart"

Regulus sneered "What a horrible name, could it be a former Gryffindor, my Lord?"

"We shall see, look into my eyes"

Regulus mentally cursed, but did as he was told. He conjured up as many safe memories as possible and coated them all with thoughts that could be related to the search of Lionheart. The mental probing he was used to during their meetings were nothing compared to this; it was only with unsuperseded willpower he didn't flinch or turn away his gaze.

It only took about twenty seconds before Voldemort withdrew again – Regulus was probably more routine than suspect. "We are done" was all the Dark Lord said.

He feigned calm as he walked across the room to the apparition spot and returned home.

He managed to get to the bathroom before getting violently ill. When he was done throwing up he just lay there on the cold floor, shivering, for hours.

The game was getting too dangerous and it was time to stop before it became the death of him.

Had he given any clue to who he was in his notes? No, not really.

Could any of the other Death Eaters give him away? Possibly; on three different raids he had stunned other followers – he had been discreet about it, but all it took was for one of the others to notice something odd.

It seemed like it was time for Regulus' plan B – the one he had thought very extreme when he came up with it; fortunately he had already laid the groundwork – after all, faking one's own death was a tricky business.

He had already withdrawn most of the gold in his bank vault, which he had then exchanged to muggle money and stashed in his old school trunk along with some personal effects that wouldn't be missed.

He was all set to go, but he had one final blow to deal to his former Master – from the shadows of course.