All characters belong to J.K. Rowling and/or Warner Bros.
AUTHOR'S NOTES: I've always admired the self sacrifice of Regulus Black, but I found it more just if he got an opportunity to save himself. This is Alternate Universe.
Diagon Alley, July 2 1979
Regulus Arcturus Black was wandering through Diagon Alley. Yesterday, after the last Death Eater meeting, Lucius Malfoy had grabbed his arm, given him a strange box and ordered him to deliver it to Borgin and Burkes. It probably contained some Dark item that Malfoy had sold to Borgin and Burkes and wanted Regulus to deliver. With a threatening voice Malfoy had admonished him not to look into the box or face the consequences if he did. Not that he wanted to have a look, it was probably jinxed. Besides, Regulus wasn't enthralled with Dark Magic or at least not anymore. He fastened his hold on the box and pulled his cloak even tighter to his body just in case anyone was following him.
Regulus still couldn't believe what turn his life had taken. When he had signed up to become a Death Eater he thought it would give him the opportunity to seek fame and glory. But he had never thought about the price he had to pay for all of that. Pleasing his parents had always been the most important thing for him, even if that meant to say goodbye to his brother Sirius and potentially damaging his soul. Not that he had given any thought to his soul either. At first he had to perform mundane tasks for Voldemort, such as assessing fellow Hogwarts students for potential recruitment or delivering messages and packages as he was doing now. His parents had taught him to think of Muggles and Muggleborns as inferior beings but that belief had crumbled down less then three months after joining.
He had been so pleased that Voldemort had selected him to part of a Dead Squad to raid Muggle homes. The home they had raided belonged to the parents of a Muggleborn girl from Hufflepuff in Regulus's year. Of course Voldemort didn't expect him to kill, but he wanted him 'to watch and learn how killing was done'. He watched and he learned but the lesson he learned was hugely different from what Voldemort had intended. When they had entered the frontyard the dog woke the Muggles inside. Avery killed the dog and Mulciber broke entry. Regulus and Avery had followed Mulciber inside. The Muggles were coming down the stairs to see what had caught the dog's attention and when they noticed the three of them the man tried to drive them back out of the house. While the man lunged forward Mulciber uttered the Killing Curse, killing him. The woman tried to flee, but Avery had constrained her through magical ropes. She had asked them who they were at which Mulciber had answered:
"We have come to escort you to Hell".
Mulciber had proceeded with uttering the Cruciatus Curse. The woman had started twitching and screaming. It had upset his stomach and he had found it increasingly difficult to keep on watching. When Mulciber had lifted the curse the woman started begging for her life. Mulciber then resumed his torture, but the woman apparently had noticed Regulus discomfort for she stared into his eyes, begging:
"Please! Make it stop! Please!"
He had averted the woman's gaze because her wailing and twitching had become unbearable to him. Avery had then uttered the Killing Curse before they left the home. Once they were outside Mulciber had patted him on the back, telling him that he should stop acting like a wimp and that the Dark Lord couldn't use remorseful killers. After those words he had desperately tried to see the Muggle woman as an animal, as his mother had taught him, but all he could remember was that a frightened human being had looked him in the eye and implored him to save her, which he hadn't done. From that point onwards Regulus knew that he wasn't capable of killing, maiming or injuring other people. The temptation of Dark Magic had worn off and he saw it for what it truly was, a cruel form of entertainment for deranged minds. Voldemort had lost his glamour too. In Regulus's eyes he sank from being a god to the Devil incarnate. Even though the episode had occured nine months ago he could still remember as if it had happened yesterday.
He turned into Knockturn Alley, down the street to Borgin and Burkes. He entered the shop and encountered Mr. Borgin behind the counter.
Mr. Borgin greeted him: "Hello, young man. You must be a Black. The noble features of a member of the House or Black can't be missed, not even by a blind man. What business brings you here?"
Regulus, not at all flattered, answered: "I'm Regulus Black. Lucius Malfoy asked me to deliver this box".
Mr. Borgin took the box from Regulus's hands and opened it to inspect its contents. Apparently the box hadn't been jinxed, because Mr. Borgin had done nothing special before opening it. Just before curiosity took the better of Regulus Mr. Borgin abruptly closed the box.
"Thank you, Mr. Black. Please convey to Mr. Malfoy my greetings and thanks. It has been a pleasure doing business with you. Goodbye, Mr. Black".
Regulus mumbled a quick goodbye and quickly left the eerie shop, eager to get out.
After witnessing the murder of the Muggle woman Regulus considered leaving Voldemort, but nobody had ever left the Death Eaters successfully before and Regulus hadn't been sure about the course of action he had to take. In the meantime he had to hide his doubts to Voldemort who, as Regulus had found out, was highly paranoid. Fortunately Regulus wasn't an important Death Eater and Voldemort found it more important to keep an eye on his most powerful followers. Nevertheless Regulus continued to follow Voldemort's orders, which luckily enough didn't involve any further killing or torture. Six month ago Voldemort had asked Regulus for the services of Kreacher, Regulus's house elf. He wanted to hide something. Regulus didn't trust Voldemort at all, but had to agree to his request anyway lest Regulus's discomfort became known to him. But Regulus had ordered Kreacher to come back, no matter what happened. Kreacher returned and told him a very gruesome tale. Voldemort had been hiding a locket in a flooded cave near the sea. Voldemort had sailed to an island in the centre of the cave, where a basin was located. The basin contained a poisonous liquid, which made whoever drank it extremely thirsty. Voldemort had forced Kreacher to drink it and then left Kreacher to die. Only his order and Kreacher's different Apparation abilities had ensured Kreacher's survival. Thinking about it still made Regulus furious. No matter how little Sirius and his parents understood, to him Kreacher was family and Voldemort had tortured him. Regulus was determined to make him pay for that.
During the last months Regulus tried to find out more about the locket. Voldemort had been telling them that he had found a way to become immortal. Through those few clues and months of research about the locket Regulus managed to find out that Voldemort had turned it into a Horcrux, a device in which a part of one's soul can be stored. Voldemort had ripped his soul and had stored part of it in the Horcrux. If he created enough of these things Voldemort would achieve immortality. Regulus knew he had to act, but uncertainty had plagued him. He had entertained the idea of defecting and giving the information about the Horcruxes to Dumbledore. However, he doubted Dumbledore would believe him. Dumbledore was a powerful and educated man, but Regulus didn't think Dumbledore knew about such Dark Magic. And even if he did know Dumbledore might be suspicious about the information or think it was just a ruse by Voldemort to spur him to reckless action. He had then thought about visiting his brother Sirius and come clean about being a Death Eater and his discovery. But too much had happened between them and Sirius had always been impatient. Sirius wouldn't have the energy or the will to listen to him.
He had come to the drastic conclusion that he had to destroy the Horcrux himself. Through repeated questioning of Kreacher Regulus had managed to roughly locate the cave and tonight Regulus would go there to destroy the Horcrux. Kreacher would accompany him to help him but there was no chance that he would let Kreacher drink the liquid. The elf had suffered enough and if Regulus had to sacrifice his own life to spare Kreacher another torture he would do it. Nevertheless, he found it difficult to come to terms with that fate. It wasn't the possibility of dying that bothered him most, it was the idea of getting poisoned. If Kreacher's account was true his death would be an agonising one. Kreacher bothered him too: what would be his reaction to him drinking the liquid? Kreacher was fiercely loyal, but would Kreacher let him drink the potion? Or would he try to stop him? Voldemort forcing Kreacher to drink the liquid was nothing short of torture, but Regulus didn't think having Kreacher watching him die was much better. He had to order Kreacher to leave him before Kreacher realised what he was doing. He also feared Voldemort's reaction to his disappearance. Not that he could harm him in death, but he would assume he had defected. What would he do then? Retaliate by killing his parents? Or Sirius? Or Kreacher? Regulus didn't know whether his plan was a good one, but doing nothing to stop Voldemort was worse.
Still thinking about his plan, he reached Diagon Alley again and as he turned the corner he bumped straight into a man.
"Can't you look where you are going", the man said.
"I'm sorry, I wasn't paying attention", Regulus answered.
The man wore glasses and his black hair was unkempt and messy. He was accompanied by a woman his age with long, rolling red hair. They looked strangely familiar and just as Regulus was about to get on his way again the woman remarked:
"James, doesn't this man look just like Sirius?"
"Yes, now that you mention it", James replied.
Regulus now recognised the couple. The man was James Potter, the best friend of his brother Sirius and the woman had to be Lily Evans. Hadn't Severus Snape fancied her?
Regulus wanted to walk away, but James drew his wand and pointed it at Regulus.
"Where do you think you are going, Regulus Black? I think it's best you stay here until the Aurors get here", James told Regulus.
James then turned to Lily and said: "Lily, go and warn the Aurors".