A/N: Sometimes the writing bug bites. Sometimes it bites hard. This has been some degree of in progress for 18 months now, and the current draft is version 6. I'll answer questions as they come up but there'll be no major ships, bashing, etc for the foreseeable future. I'm also doing my best to squish HP canon in line with history. It's mostly working.

Update schedule will be Monday mornings PST going forward. I have 3 chapters edited and 18 written, and hope to pad that out to 5 and 20, respectively. This is a long, long fic that I have every intention of taking through 1998, but the writing is in 1981, so buckle up.

Thank you to my betas, sabreprincess and noaacat, for catching grammar/historical/characterization/continuity/spelling errors and generally putting up with me.

Regulus had thought OWL year was bad enough, but NEWT year was ten times worse. Sure, he had dropped some classes, but he was now a Death Eater, and the Dark Lord had no understanding of how much time he needed to spend revising.

Take the last week for instance: He had been planning to spend Easter hols frantically cramming, but an owl had come two days before classes ended. So he had come home, back to Grimmauld Place, and every night so far he had been summoned. He had the afternoon to study, but his mother liked him to spend the mornings attending on her, and that left him only six hours a day and that just wouldn't be enough.

Six hours—if nothing went wrong. Two nights before, he had misspoken to the Dark Lord and had been punished, and yesterday he had been able to do no revising at all, and tonight was Saturday, with the train back tomorrow morning and he was only just starting to revise for Transfiguration.

With a sigh, he pulled out his notes on complex human-human transfigurations. They had only been introduced right before the holidays as the last topic on the NEWT, and he didn't feel like he had any sort of grasp on how they worked. Most transfigurations were from object to object, dog to drawer and so on, or from property to property, red hair to green. But complex human-human transfigurations turned one person physically into another person, and the theory was, as per the name, complex.

He'd spent barely fifteen minutes on them, just enough to have a formal definition worked out, when his arm started hurting.

Regulus yanked up his sleeve, glaring at the mark on his arm. The Dark Lord had told him he would have the weekend off and it wasn't like him to lie. Perhaps the summons was accidental.

He waited a moment, but the pain didn't vanish. Groaning, he rolled up his notes, shrugged his black over-robe on, and left his room.

Across the landing was Sirius's door, closed.

Jaw clenched, Regulus stormed down the stairs. He couldn't be annoyed at the Dark Lord, but it was easy to think about Sirius instead, how Sirius had abandoned him and betrayed him, and with that Regulus could truthfully say his anger was at his brother.

He slowed down and softened his steps as he approached the first floor, where his mother's sitting room was, but no luck. "Reggie? Reggie! Where are you going?"

Putting a smile on his face, he poked his head into the room. "He's summoned me, Mother."

She gave him a look over her reading glasses—which she wore for show, not for reading—but only said, "Give him my best then, dear, you know he loves to hear from me."

Regulus knew perfectly well the Dark Lord did not appreciate being reminded that Walburga Black still held a schoolgirl crush, but dutifully he bowed his head. "Yes, Mother."

"Run along, Reggie, don't keep him waiting."

As if. "Yes, Mother," he said again, and left quickly.

Out of the sitting room, into the main hallway, down a last flight of stairs and out the front door. The majority of the wards ended at the front step but the anti-Apparition ward extended to the road outside, to slow down any attacker, his father always said. Regulus disillusioned himself before leaving the house, ran to the road, and Disapparated.

He spun back into being in front of a manor. The pain in his arm faded. Straightening his robes, Regulus approached the front gates, and showed them the Mark on his arm. The gates swung open, enchanted to respond only to the sight of the Dark Mark. It was one of the security features the Dark Lord added to any manor he was staying in. Thanks to the Ministry's persecution, the Dark Lord couldn't remain in any location for too long; instead he lived in the homes of his most faithful and provided them with additional protection.

Regulus made his way towards the manor itself and repeated the gesture at the front doors. Inside it was dark and warm. No one else seemed to be around, but even after only a year of attending meetings, Regulus knew better than to assume he was not watched.

Confidently, he followed the pull from his Mark towards his lord and master. In some ways it annoyed him to bow and scrape to any other, he who would one day be the Duke of Exeter, but at the same time it excited him. Regulus might be in line to inherit the House of Black and become one of the most powerful nobles in wizarding Britain, but that only made more exceptional the man he chose to serve.

"Flattering thoughts," the Dark Lord said, coming out of the shadows.

Regulus fell to his knees and lowered his head. He hadn't even felt a presence in his mind, but he no longer was surprised by that: the Dark Lord was a legend for many reasons, after all. "My lord."

The Dark Lord touched his shoulder gently. "Rise and walk with me."

He obeyed, he would always obey; it was instinctive to follow his lord, keep himself half a step behind, show the respect the Dark Lord had long since earned.

They walked through the manor in silence for a time. This month, the Dark Lord was staying with the Rookwoods, a family nearly as old as the Blacks but considerably less influential. The highest title Augustus Rookwood had reached was that of Knight of the Realm. The manor, as such, was neither large nor richly furnished. Regulus kept his eyes down and tried to control the criticism he knew his mother would have unleashed.

"Do you have a house elf?" the Dark Lord asked suddenly.

Of all possible questions, he had not seen this coming. He said cautiously, "My parents own two, one of which was given for my personal use on my majority." Kreacher still answered to his parents, of course, but only Regulus generally gave him orders. "I need use of one," the Dark Lord said, continuing to walk, "an obedient one that will not gossip."

Regulus noted another area of magical tradition where his lord was lacking. House elves obeyed whoever fed their magic, and only gossiped to other elves. He had known since the day after his induction that the Dark Lord had not been raised in a magical family; he suspected that had been why he had been recruited so young. As an heir to the House of Black, he had been raised knowing both all the ins and outs of magical society and how to keep a secret. The Dark Lord had need of both.

Not letting any of this leave the deepest reaches of his mind, Regulus said, "Of course, my lord. My elf is very well trained. It would be an honour to have him serve you."

"Send it to me." The Dark Lord stopped and turned to him, red eyes meeting Regulus's. "That is all."

He bowed and backed away from the Dark Lord. While it was not quite taboo to turn your back on the Dark Lord, it was still dangerous, a danger Regulus did not wish to court.

The Dark Lord ignored him, and walked away.

When Regulus was sure he had gone, or as sure he could be, he turned and made his way back to the entry. The Dark Lord was clearly preoccupied with some new problem that made him more terse than usual. Regulus was pleased with this: he would still have time to revise after returning home.

He first wondered if the Dark Lord wanted Kreacher for whatever problem he was working on, then abandoned that thought with a laugh. Anything the Dark Lord could be up to would surely be more impressive than a house elf. No, he probably wanted Kreacher to clean the manor.

As he left the entry to the manor, he ran into Rabastan. The older man grinned to see him and ruffled his hair. "Good evening! What's his mood?"

Regulus ducked away, flattening his hair again. "He's terse, but otherwise normal. Watch your thoughts, though."

Rab shrugged, movement loose. "I come with good news," he said smugly, "there's no reason for him to go looking."

He thought Rabastan was being rather cocky, but so be it. It wasn't like Regulus had come with bad news—or any news at all, for that matter. The thought of his disrupted study annoyed him again, and Regulus said waspishly, "But how much do you want him to know about your sister-in-law?"

Rabastan stared at him for a moment too long, shocked out of his smug superiority of being-four-years-older, and Regulus grinned at him and Disapparated.

Something became nothing became something. Regulus appeared across the street from Grimmauld Place and slipped inside and downstairs to the kitchen before his mother could catch him.

"Kreacher!"

The elf was at the kitchen sink, a plate in his hand. He must have been cleaning up from dinner. "Master Regulus is back. And in Kreacher's room."

Regulus ran a hand through his hair, unsettled by what he had to ask. "I wanted to talk to you away from Mother."

Immediately Kreacher looked sceptical. "Master Regulus knows—"

"Many things," he said smoothly. "Right now, I know that you don't have to tell Mother what I do unless she asks, and she's not going to ask about this."

Kreacher frowned but said nothing.

Regulus tried a winning smile. "The Dark Lord wants your assistance tonight. I want you to go to him and do whatever he commands. When you come back, make no mention of it to Mother, is that clear?"

Kreacher's ears went flat back in offense. "Kreacher does not serve the Dark Lord! Kreacher serves the Ancient and Noble House of Black."

"And this member of the House of Black serves the Dark Lord," Regulus said, "and he wants an elf. It is an honour to serve him. If Mother asks what you did tonight, you don't have to lie to her—"

"Kreacher cannot lie to Mistress," the elf said sulkily.

"But I command you to avoid bringing it up with her or mentioning it," Regulus finished.

Kreacher twisted the end of his ear, turning this over. "Master Regulus wants Kreacher to go to the Dark Lord and obey and not mention this to Mistress."

"Yes," said Regulus, relieved. "I'll tell Beist that you won't be home tonight. Mother never needs to know."

Still sulky, Kreacher bowed. "Does Master Regulus have any other inconvenient orders for Kreacher?"

Regulus grinned at him. "When the Dark Lord is done with you, come home and pack my things for school."

Without reply, Kreacher snapped his fingers and vanished.

Regulus made his way to his bedroom, pleased with himself.

Kreacher hadn't returned that night. Regulus had been revising Transfiguration until the wee hours, but the elf hadn't popped into his room before he crawled into bed at one—nor after, by the state of his messy room when he woke the next morning.

He frowned. Surely whatever the Dark Lord had wanted wouldn't have taken this long. Kreacher could do a perfunctory cleaning of even a manor in a matter of hours, for something to have taken the whole night would mean the Dark Lord had ordered a cleaning much deeper than he had the right to as merely the borrower of the house elf. But did the Dark Lord know that?

Regulus didn't think he did.

Of course, he couldn't very well go to the Dark Lord unsummoned and say he needed his house elf back to pack his belongings for school.

No, Regulus decided, he would just have to pack for himself. Sighing, he waved his wand and watched belongings begin to pack themselves in his trunk.

By the time he arrived on the platform, he was beginning to be seriously worried. There was only so long he could hope to conceal Kreacher's absence from his mother, and he had just lost any opportunity to make excuses about it. Fortunately he himself would be safely at Hogwarts for the next month, but after that, he could only imagine the words his mother would have in store for him for lending an elf, even to the Dark Lord. Never mind the crime of hiding it from her in the first place.

As a Slytherin prefect, he was supposed to patrol the carriages, but seventh years generally left that to fifth and sixth years, and he quickly found an empty carriage and locked the door. If Kreacher was dismissed at this point, he would come find Regulus first, and Reg didn't want any witnesses to that conversation.

That foresight came in handy two hours later when Kreacher popped into the car and collapsed on the floor, breathing hard. He was dry, but absolutely reeked of seawater, and looked beyond exhausted. "Kreacher is sorry, Master Regulus, Kreacher did not mean to be late, Kreacher tried, Kreacher tried and tried but Kreacher could not pop very far, Kreacher is a bad, bad elf for not packing Master Regulus's belongings—"

Regulus fell off the seat and onto his knees in front of the elf. "Kreacher, stop. What happened? Why couldn't you pop back to me?"

Kreacher looked up at him, eyes bloodshot. "Kreacher could not, Master Regulus, Kreacher was too tired."

"What did he do to you?" Regulus asked, voice weak with shock. House elves could get tired, yes, but it took more than a day's work to do it. This smacked of torture and abuse, and while Regulus accepted that punishments sometimes needed to be handed out, Kreacher was his elf. Not the Dark Lord's. The Dark Lord should have come to him if there had been any problems.

Shaking his head, Kreacher managed to get into a sitting position, though his legs were trembling. "The Dark Lord ordered Kreacher to—" His voice caught, broke. "Kreacher was ordered to—"

Carefully, Regulus touched Kreacher's shoulder. "I'm ordering you now, Kreacher. Tell me what happened from the moment you left me last night."

Kreacher took a raspy breath, and obeyed.

By the end of his story, Regulus was white with shock—and rage. First, Kreacher had been kept cooling his heels in a waiting room for hours, until well into the night. This was disrespectful to Regulus, as well as hard on Kreacher to spend so much time inactive, but then. Then the Dark Lord Side-Along'd Kreacher to a godforsaken cave in the middle of nowhere and proceeded to place a number of wards, Dark and otherwise, on the entrance to the cave, before putting what Regulus knew to be a very complex spell on a sheer wall deep inside the mountain.

And then Kreacher had had to wait again, in a cavern filled with a dark black lake, while the Dark Lord summoned Inferius after Inferius and stationed them in the bottom of the lake, to attack any who touched it. Inferi could only be created by the one who killed them—the number was disturbing to Regulus, but not truly surprising.

But then the Dark Lord had grabbed Kreacher by the back of the neck, and pushed him into a tiny rickety boat, and moved the boat across the lake to an island at its centre, where there was a basin with a liquid in it that was not water.

The Dark Lord had ordered Kreacher to drink it.

Kreacher had.

It was at this point that his story had broken down and become disjointed. Kreacher had clearly drank some sort of poison—perhaps not a fatal one, but he looked sick and that was on top of the mental effects. The elf was sobbing as he talked, and his sentences were broken up by out-of-place pleas for something to stop. Then the Dark Lord had put a locket in the basin—a locket Kreacher had been disturbingly focused on, a locket that to Kreacher's house elf senses had reeked of powerful magic, emotional magic, dead magic—and filled it with potion again.

And then the Dark Lord had left on the boat, leaving Kreacher gasping and crying on the rocky island.

The potion contained a thirst component, Regulus guessed, because Kreacher had gone down to the water and tried to drink from it. The Inferi had grabbed him, and in that moment the Dark Lord had left the cave. With that, Kreacher had no longer been bound to obey him, and could pop back to Regulus.

Or try to.

Kreacher had torn himself loose from the Inferi, but the cave had been protected even against house elves, so Kreacher had had to make his way back to the entry before popping away.

Exhausted from the potion, Kreacher had only been able to move a few miles at a time, and from the way he was talking, the poison hadn't left his body yet. It had taken him well into the morning to get close to the train tracks, and then he had rested until the train approached him.

It was good thinking from anyone, let alone a poisoned and exhausted house elf, and Regulus praised him for it.

Kreacher was still shaking when he finished, drawing his knees up to his chest with his ears tightly pressed to his head.

Regulus stared at him as the train rumbled on, trying to find a place to start. The Dark Lord had to think his elf was dead—the Dark Lord had asked to borrow Kreacher believing that Kreacher would not survive the experience—what kind of good-for-nothing ill-bred moron did that? An honour, he had called it, an honour for Kreacher to serve the Dark Lord.

He rubbed his hands over his face. "Beist," he said quietly. First things first: his mother.

The other Black house elf appeared, scowling. "Beist knows Master Regulus is not supposed to call her," she told him sharply, only then noticing Kreacher. "What has Master Regulus done to Kreacher?"

Regulus breathed out heavily. "He is sick, Beist. It is not his fault, but he needs to stay with me for a day or two and recover, do you understand?"

"House elves do not get sick," Beist said. "What has Master Regulus done—"

"Wizard's business," Regulus told her, cutting her off. "Go home and do not mention this to Mother, am I clear? Perform your tasks and Kreacher's and do not tell or hint to Mother that he is sick."

Beist bowed and vanished, silent and judging.

Well that was one thing done. Kreacher was still curled up, and Regulus looked at him guiltily. If he hadn't let the Dark Lord borrow him—but how, how to refuse a wizard like that, how to refuse someone you had sworn allegiance to—but what power was in vows that were twisted like this, vows given to one who did not understand their power? The Dark Lord was his liege but he was Kreacher's, and to give one unto the other for a plaything—

"Kreacher," Regulus said, chest tight. "Get into my trunk. You need healing and I—Mother cannot know."

The elf uncurled himself and hobbled over to Regulus's trunk. "Kreacher is sorry, Master Regulus, Kreacher is sorry Kreacher is sorry Kreacher is sorry—"

"Shut up!" Regulus stared at him and for a moment didn't know what else to do. "It…it doesn't feel like it right now, but you didn't do anything wrong, Kreacher, I promise. You did a lot of things very right, but right now I need you to get into my trunk and keep quiet."

At that Kreacher got in the trunk, leaving Regulus to sit quietly in an otherwise empty carriage.

They arrived at Hogwarts hours later, and Regulus went quickly to the Slytherin dorms to put his trunk at the foot of his bed. The boys in his room had long since reached a truce regarding personal possessions and he didn't seriously worry about it being disturbed. With that done, he went to Professor Slughorn's office.

Slughorn didn't hold office hours during holidays, but Regulus knew he didn't leave the castle either, and he thought the Potions Master more useful for this than any other teacher.

The door swung open a moment after he knocked, and Regulus stepped into the office. Sometimes he wondered if the other Heads of House offices looked anything like this: stone walls covered in wooden bookshelves, and the shelves filled with pictures and trinkets, each from a favoured student. He was already thinking about what to give Slughorn after graduation.

"Ah, Mr Black," Slughorn said from behind his desk. "A little early to be seeing you about extra Potions, isn't it?"

It wasn't an act to shuffle his feet, look at the floor. "A little, sir. Truth is, I had a question about a potion for you. A poison, I think."

Slughorn raised his eyebrows. "Is this really a matter for a professor?"

He dismissed the concern. "It's purely academic, professor. I just need to know the name." He thought, added, "And the antidote."

"Purely academic?" Slughorn sighed and shook his head. "Well, you know I never could resist a question from you, my boy. Have at it."

Regulus rubbed at his face. "A deep green potion, which glowed. Not immediately fatal. Physical effects: shaking, very pale. But it's mostly mental, sir, I wonder if it has powdered Graphorn. Leaves the subject afraid, deathly afraid, and convinced that they have failed someone. And thirst. They're thirsty." He tried to remember anything else that could help but didn't get anywhere. He felt sick.

"Where did you say you encountered this potion, Mr Black?" Slughorn asked sharply, leaning forward.

He felt his shoulders rise. "I didn't say, sir. If you don't know what it is…"

Slughorn gave him a stern look. "If I find out you've been using this on someone…"

"I wouldn't!" He wasn't normally rude to professors, only Slughorn had to take him seriously. "Promise, professor. This is for a friend." Or a house elf. What did it matter right now, except that Kreacher hadn't been improving and wouldn't without help. "He's sick and I think he," he swallowed, "I think he took it."

Slughorn's face fell. "The description you gave," he said cautiously, "matches a potion called the Potion of Despair. It is not by itself fatal; however, like Felix Felicis, it can act upon the drinker's future and those who drink it usually die within the week."

Regulus's stomach cramped. "Is there any—"

"Yes." Slughorn looked down at his desk. "There is an antidote. It is not cheap, and it will take me two days."

He breathed out slowly, holding on tightly to the words. There is an antidote. "I don't think, sir…" He stopped, tried again. "I doubt my allowance is enough for this. Perhaps if I could borrow the instructions."

Slughorn frowned. "You're a good lad, to do something like this for your friend."

I'm really not, Regulus thought, trying not to squirm. Not when I'm the one who got him into it.

"You are shaping up to be a fine potion maker, Mr Black, but not on this level, not yet. I will brew it for you, but…" His moustache twitched. "Brewing it and resupplying my private stores afterward will cut into my patrol time, on Tuesday and Thursday evenings, for a month, you understand?"

Regulus felt all the blood rush out of his head. He was going to do it. Kreacher would recover. "Yes, sir. I understand perfectly." Everyone knew prefects—of any house—could get a grade boost by covering some of Slughorn's patrols. This wouldn't be the first time Regulus had asked his head of house for a favour, for that matter, although a month was longer than Slughorn usually wanted.

"Come back on Tuesday, and keep your friend out of trouble until then," Slughorn said, turning his attention back to his newspaper.

Regulus nodded, and went to go to bed. Whatever happened, he had a plan to help Kreacher, and that would have to be enough.