A/N: Kind of an experiment to post this as I write it. I'm not sure how long it's going to be, but I will aim for fairly frequent updates on Fridays. First few chapters are already finished, and my muse seems to be in love with the story, so with luck it'll be done before long and I can come out with an exact posting schedule.

You do get the first two chapters together (lucky you!), because they're both fairly short compared to the third, which, if you know my writing, may be common, may not. Depends on whether the characters cooperate.

Debt To Repay

Hermione Granger did not do well with mysteries. They felt like secrets, like lies, and worst of all, it was knowledge she didn't have. And that was unacceptable. Since the war, she had made it her business to route out mysteries around her. Nothing survived her scrutiny long. Except one lone mystery that drove her to the brink periodically.

How did Severus Snape survive the Battle of Hogwarts?

He'd been dead, she was so sure of it, by the time she, Harry, and Ron had left him in that grotesque pool of his own lifeblood. Yet, when Harry had gone back with McGonagall and an equally forgiving Neville to retrieve the body, they'd found Severus Snape clinging to life. Some kind of unidentifiable magical stasis, preserving the last vestiges of his black soul and just enough blood to keep his filthy organs functioning. How? Harry hadn't cast anything, she'd have seen it, but the magic was inexplicable, and there were no other viable answers besides him and his ever-escalating number of magical impossibilities.

Part of the thing that drove Hermione spare, whenever this mystery surfaced to tickle at her senses, was that she knew where she might easily find the answer. Surely, if information on the strange magic existed, it would be in the Department of Mysteries. Except they'd rejected her application. She'd failed the psychological examination, apparently. Something about a skewed moral compass when it came to judicious action, and reckless behavior that belied impulse. She understood the results, but seeing as those traits had helped her and her friends survive the sociopath out to kill a boy she thought of as a brother, she was of a needs must mindset about it. The Department felt that wasn't an adequate, or healthy, response to basically being told she wasn't mentally fit to contain the secrets they protect.

She suspected it was her unrepentant "yes" answer to the question of whether she would ever do something knowingly harmful or dangerous to protect a loved one, or to enact vengeance on a threat against them. Damn them for only interviewing under the influence of Veritaserum and other, unknown, truth magics.

Either way, she didn't have access to the one place that might tell her the type of magic that had kept Snape alive, but it didn't stop her determination in finding out the power behind it, or the reasons why. He hadn't deserved that second chance at life. Not when so many better and brighter souls were lost. He definitely hadn't deserved the dedication Harry had put into clearing his name and ensuring he walked out of St. Mungo's months later a free and celebrated war hero.

So, periodically, this mystery would eat at her. Particularly when she had to see him, or heard his name, or was reminded of the battle… so a lot, even two years after the war.

It wasn't until the summer following the second anniversary of the battle that she finally got her answers. And she would forever deny to any who asked that it happened completely by accident. Maybe it wouldn't take a genius to put all the puzzle pieces together, but she was convinced no one but her could have done it so quickly. Only fools relied on luck, and she'd take to her grave that it was exactly that, lucky circumstance, which gave her the answer she so craved.

Harry falling ill at a routine Sunday family dinner was the first unusual happenstance. It had led Hermione, the following day, to Diagon Alley and Brewed Glory, Snape's apothecary. Hate the man as she did, she had to admit he made potions that were unrivalled. Besides, Harry wouldn't trust anything brewed anywhere else. He even preferred Snape's potions over hers, which she had no qualms feeling insulted over, claiming he had been biased against her by the Half-Blood Prince.

Harry had shrugged her comments off and insisted. Which, for once, she'd been glad for his stubborn streak, since it gave her a glimpse she might otherwise have never gotten of Snape's left wrist. The man must've gotten used to no longer having to hide his Dark Mark, because it had taken him a moment to roll his sleeves down when she'd walked in as soon as he was open. And there, where the Dark Mark had been, was a brand-new brand, red, raised, scorched into his skin. It took viewing it a few times in a borrowed Pensieve to realize what the mark was.

Snape had been branded with the Potter family crest. Finally, the pieces were clicking together, and after a few weeks of research, she had her answer. Her first instinct had been to tell Harry, but he'd either ignore it or get angry at her for poking her nose in. Her second instinct was Ron, but her boyfriend would inevitably tell Harry. For some reason, Ron had started taking Harry's side when it came to Snape after the battle.

That left her with one option, one person who could not only keep it a secret but could also use the information far more than she could. And Ginny had just as big of a grudge to settle with the greasy bat, so it worked out perfectly. On Harry's 20th birthday, it was his brand-new fiancé who got the best present, in the two witches' opinion.

One Year Later:

Severus looked up as the bell over his door rang, announcing a customer, and wondered if he could use it as an excuse to get away from paperwork. Cocking his head slightly, he studied the sounds of the footsteps as they approached the counter, where his clerk was ever ready with a patient smile that he would never possess. Dragon-hide, expensive by the sound, and the owner was clearly uncomfortable in what Severus suspected were new boots. But the tread of the footsteps, the weight and slight scuffling, was very familiar after years of listening for it in darkened corridors, the only sign of the tread's usually invisible owner.

Severus smirked, and something animalistic in his chest purred, not only in response to the attraction he'd long ago given up denying. He knew the boy could be clever, but he hadn't expected him to be that clever, nor that quick. Straightening from his hunch over the shop's books, Severus slid out from behind his desk and moved out into the front. He waved away the girl at the register, who smiled knowingly before going about restocking the liniment shelves.

Potter, who only knew subtlety about half the time, waited until she was far enough away from the counter for them not to be overheard, before finally approaching from where he'd been perusing a display of sleep aids. It might've been a good ploy if Severus hadn't spent six months developing an aid specifically tailored to him not long after the shop had been established.

"What can I do for you, Mister Potter?"

Green eyes sparked, and the figurative creature in Severus' chest purred all the more. Oh, but the boy was very clearly pissed. Severus looked forward to the fallout, and to enjoying the sparking magic and righteous fury while it wasn't directed at him. Truly, there were few things more stunning than Harry Potter on a warpath. A fact Severus had finally acknowledged and accepted only when that warpath had been his, and Potter had battled tooth and claw in his name.

"Perhaps you can help me solve a mystery, Severus," Potter bit out in clipped tones. "You see, there's been this odd trend within my home the past several months, and I find that the only common denominator I can locate is you."

"Oh?" Severus asked, not terribly surprised.

"Gin's been receiving some terribly interesting favors, you see," Harry went on, his voice still simmering with an undercurrent of anger. "An opening on the Holyhead Harpies after an accidental poisoning? From, apparently, a poorly brewed batch of Pepper-Up bought here. The Harpies moved Gin up to first string because of that. Then, I've also noticed that our joint bank account has been skewed. There's more there than there should be. There might not be, except inexplicably whenever Gin acquires some pretty jewelry or a new robe, they're simply gifts, and if she should get dinner out or get her hair done, it's complimentary, celebrating our engagement, or her promotion, or… well, any excuse she can come up with, really."

"Sounds like a string of uncommonly good luck for your fiancé," Severus offered, waving for Harry to follow him into the back office.

"Yes, so she claimed, and it was all circumstantial, I'll admit," Potter agreed. "Until she came to me this morning with tickets that arrived in the post, and a story about taking Hermione for a girl's weekend for a belated birthday present."

Severus led Potter to the side of the room across from his desk overflowing with paperwork, to the small couch and chair he kept by the floo for his later nights balancing the books or brewing. He took the chair, arching an eyebrow curiously when Potter refused the couch in favor of standing a few feet away. Potter was tense, and his arms were crossed in a way that unfairly flexed and highlighted the muscles of his chest biceps beneath his tight Muggle shirt.

"Tell me, Severus, how did Ginny, a Weasley, come to have two free tickets to Draco Malfoy's new resort? He didn't do it for me, because as a silent benefactor I can get tickets when I damn well please, and they'd have been stamped especially for my account there, the invitation much more personalized; and he certainly wouldn't have done it for her or Hermione, not even if he had charged his usual over-the-top price," Potter demanded. "Not for the opening invitation-only weekend. And I know of only one man he would've sent a last-minute invitation for."

Severus considered how best he could, feasibly, respond without breaking the oath.

"Why are you doing favors for my fiancé, Severus Snape?" Potter nearly snarled. "And don't you dare lie to me."

That figurative purr was back as Severus smirked. There it was. The order to override the previous order. "A Vassal Bond," he bit out, still slightly wary of a backlash, since the full wording hadn't been present. When no pain was forthcoming, he continued. "There are mitigating circumstances to it having been formed, but I am, essentially, at the service of the Potter household. This extends to the woman currently wearing the Potter bonding ring."

Potter sucked a deep breath through his nose. "What?" he hissed.

Severus nodded. "Indeed. The explanation is longer than you likely have time for, as I presume you came on your lunch break to avoid rousing Miss Weasley or Miss Granger's suspicions. The short version is that, last year, a Vassal Bond was formed between myself and the Noble House of Potter. Miss Granger and Miss Weasley came into this information and have been using it to garner… homage from me. Or to deliver unto me specific orders. The first being that I was to lie to you about the Bond, and that I could in no way make you aware of it."

Vibrant green eyes slid shut in something akin to pain as Potter muttered some very uncomplimentary thoughts regarding his beloved fiancé and his best friend. He opened his eyes to finally move to the couch, sinking onto it and bracing his elbows on his knees.

"So, she screwed up, that's the only reason I'm even aware of this," Potter said a little uncertainly.

"Only in as much as she failed to give me a specific directive with this last… favor," Severus admitted. "She told me she wanted a holiday weekend with Granger, something that could relate back to you if anyone should question where she'd garnered the favor. Since I knew Draco received your silent backing the same as I did, and a few others, and that he'd planned to give you a permanent suite for your private use in return, it seemed fitting. She would accept that the holiday could be an assumed favor from Malfoy on your behalf. I hoped so, at least, since I was admittedly unsure if what you said a few months ago about keeping your finances separate was still true this close to the coming wedding. I hedged my bet by making the reservation in my name, ensuring she received one of the mass invitations, and not the privatized invitation you would know to expect. I will admit I didn't expect you to put together the dots of the favors so quickly, not at least without speaking to Draco first, since he, too, questioned my reservation."

"I've suspected ever since the incident with Gin and the first-string Chaser," Potter said hoarsely. "I know your work, and you personally test every potion sold on your shelves. That the entire tainted batch had only sold one bottle, in the middle of winter, raised my hackles, but Ron insisted there was nothing in the report, yours or hers, that suggested it was anything more than bad luck. I took it for coincidence. And whilst the other favors and 'gifts' all related back to the Alley in some way, Ginny has always been more receptive to my fans than I am, so I tried to ignore the itch that told me it went deeper than that.

"I didn't have proof, and didn't want to rock the boat too much if it turned out my suspicions were wrong. God forbid it turn out she was stealing, or sleeping with some rich benefactor, I wasn't sure I wanted to know. Draco's involvement finally allowed me to narrow my suspicions down to always coming back to you, and since I know you better than to ever think you'd sleep with Ginny, it had to be something worse. My bad luck that I thought blackmail was the worst possible outcome."

Severus winced. Yes, he supposed abusing something that equated to a slave bond might seem worse than blackmail. "What will you do?"

Potter rolled his shoulders and stood. "Something I should've done a while ago," he said softly.

Severus was on his feet with a hand wrapped around a firm bicep before the boy could storm past him. "Harry."

Potter drew a deep breath. And then another. When he opened his eyes, the anger had cleared a little. "Yeah, nothing rash, I know," He said with a strained smile.

"So, what will you do?" Severus asked again.

"Has she had to pay for anything even once since she discovered the bond?" Potter asked curiously.

Severus hesitated. "Not as far as I know, and nothing on the Alley. Why?"

"Then the first thing I'm going to do is empty that joint account into your vaults," Potter said stiffly. Severus opened his mouth to argue, but Potter cut him off. "You will accept it, by order of the Noble House of Potter, as recompense for my House mismanaging your estate."

Severus bit back an angry response. Augusta Longbottom's teachings had clearly paid off, as that was the exact wording necessary to not only enforce the order, but excuse repayment under the bond. "Do I have to be gracious about it, my Lord?" Severus sneered.

Potter's smile became a little less strained. "I think I'd worry if you were. Besides, it isn't my money, Severus, it's hers. The joint account is her income and only a small portion of mine. Since that portion of mine is mostly my monthly expenses, anything you get that can still be attributed to me can be funneled into your business. I'm an investor, it's not unusual."

Severus decided he could live with that. "And after Gringotts?" He asked a little worriedly.

"Nothing that will implicate you," Potter assured him, reaching across to touch Severus' arm. "Ginny seems to have forgotten, in her bid for power, that I am still very much the Boy-Who-Lived-Twice. Captain Jones still owes me a favor for getting her out of Slughorn's last shindig, and Gin's missed a few practices since becoming first-string."

Severus smirked, loosening his grasp on Potter's arm. "I take it, then, that Miss Weasley won't be a Harpy for much longer."

Potter's smile became something of a grimace as he stepped away and started towards the door. "Sorry, Severus, but not even I can make her any less of a harpy, apparently."

Severus stifled a laugh as he watched Potter leave the shop. He felt bad that Potter had been caught up in this storm, and that the girl he'd been engaged to for more than a year had betrayed him, but he couldn't find it in him to regret it. No more than he could regret any part of his association with Potter since the war had ended. If nothing else, Potter made his life much more interesting, including the weekly cases he brought him.

During Severus' brief convalescence in St. Mungo's after the final battle, Potter and he had spent quite a bit of time together. It helped that Severus had been unable to shout him out of the room or curse him. His throat and magic had been equally ravaged by Nagini. By the time either had healed enough to facilitate Potter's removal, he'd deemed it… unnecessary. It was clear Potter was using his hospital room as a refuge as much as he was helping manage Severus' care. Besides, the healers paid far more attention to him when Potter was there, rather than ignoring him for hours upon hours on end for what they perceived his role in the war had been.

After three weeks of listening to Potter talk, and moan, and occasionally whine, about his life and struggles in the aftermath, Severus had come to acknowledge that he may have, perhaps, given the boy a poor turn in assuming he was his father's son. He certainly had quite a bit of James' influence, but his stubbornness and near passivity to defend himself whilst bracing against the gates of hell to protect everyone else was all Lily.

When he had finally first begun regaining his voice, sooner than his magic, he'd thought the visits would reduce in number. Instead, Potter began coming every day. Severus eventually parsed out that Potter was in desperate need of a friend, one not currently in mourning, and who understood the toll the war had taken on him, was still taking on him in the aftermath. It had been surprisingly easy to slip into that role, in part because Severus could have used that exact thing after the first war. So, they became such for each other.

Severus still couldn't comprehend how Potter could just forgive so much of who he was and what he'd done in the past. Never mind how he'd convinced so much of the public to do the same. Potter had shrugged and told him not to think about it too hard. Since Severus was a Slytherin, and not one to look a gift horse in the mouth, he'd taken what he was being offered. Granted, he'd been less gracious when he discovered the investment firm that had helped him and a number of disenfranchised Slytherins reestablish themselves belonged to Potter, but Potter took his blustering with grace and had allowed him to renegotiate the contract to something slightly less generous.

Now, going on four years after the war, Potter was still taking on "charity cases" as Severus called them. Not only investments, he helped in whatever way he could, using connections or calling in favors. For a boy who'd never wanted to be famous, he'd learned quite well how to use it to his advantage. Augusta Longbottom had had her hand in that, when she'd forced Potter to accept the mantle of Head of Household for the Noble House of Potter. That it had only been done so he would have sway in the Wizengamot and better assist in the Death Eater trials was neither here nor there. Potter had assimilated the political knowledge well, adding it to his impressive repertoire.

He was determined that if his name had to go down in history books one way or another, it might as well stand for more than what Potter essentially broke down to a lifelong revenge streak against the madman who killed his parents.

Of all the possible uses for Potter's dual-fortunes from his parents and godfather, and all the possible careers, even Severus had been surprised that 'Selfless Gryffindor' became the brat's more-or-less unofficial calling card.

It was a good cover for a boy who felt as equally stained as Severus himself did, after the actions they'd each taken during the war. Severus' penance had been being imprisoned in a school full of ungrateful children and suspicious colleagues, beholden to an old man he loved and hated equally. Potter's penance was more self-imposed, but no less heavy on his shoulders.

Severus couldn't help wondering, as he returned his attention to balancing his books now that he knew he had quite the influx to prepare for, what this new source of guilt would do to the young man he had, admittedly, far too much affection for than was strictly appropriate. The last thing Potter had needed was another stain on his soul. It was part of why he'd tried to hide the bond. He should've known his luck and Potter's would never have allowed that.