Chapter Text
He did not lust after immortality as his Lordship had, but Severus Snape was not going to let some handsome tosser with a snake obsession and daddy issues cut short the one life he did have. He figured he had probably by now (the time our story starts) missed the window in which he might have passed on his DNA, but the youthful righteousness that had long ago told him that he didn't deserve to be murdered and simply wasn't going to be - that lived on.
If he learned anything from his childhood home, it was that his life mattered (from his mother) and that if he wanted to survive, he’d damn well better figure it out for himself (from his father).
As a younger man, of course he didn't put blind faith in his determination itself saving him; he planned. He schemed. He lined up details, fabricated evidence, had a peck of onion's worth of layers to the lies he spun, his own personal mythology. Inside of the onion in the center of all the other onions was an ouroboros, the head of which was Severus Snape cannot die because he will not allow it and the tail of which was Severus Snape will not allow it because he cannot die.
So, when his Lordship had crawled out of the grave fourteen years after his downfall, it was to Severus he had come, for Severus had answers. So many answers. Answers based on meticulous research and an uncanny understanding of his Lordship's emotional reality. Slytherins were not a particularly academically-oriented lot, and Severus was far and away the closest of any of them to a Ravenclaw. His raw intelligence was indisputable and garnered grudging respect from those around them, but nobody except perhaps Severus himself ever appreciated the flashes of flamboyantly creative brilliance that truly set him apart. Severus appeared serious and studious, the contemplative balance to what his Lordship had fancied his own dashing impulsivity and action-oriented daring. He looked timid, meek, weak, and yet he pulled so many of his Lordship's strings, all of which he had fastened himself.
On the hottest day of autumn in 1981, a young Severus Snape was riding high, having recently gotten the Mark. The ball had been set rolling for him to get the love of his life murdered, but he didn't realize it yet. He was socializing with the inner circle, feeling less like a loser outcast than he ever had, an absolute dream come true, and he had watched, with disbelieving horror, as his Lordship had tortured and then used the killing curse on a messenger, a boy who looked to be almost exactly Severus's age, for bringing him unwanted news.
It was only the first death of many that he would witness. But before the boy's body hit the floor, Severus understood with painful clarity that someday that would be him. It would certainly be him, and not even - it would be worse. He had a Mark. He represented a significant investment of resources, time, and clout, given the potions mastery he had recently embarked upon. When it was his time to go, it would hurt worse than what had just happened. Nobody walking then on the earth could fill the hole, the barely-cauterized sucking wound that was his Lordship's heart, and someday, without serious intervention, he, Severus, would fall into that hole.
He had a natural talent for Occlumency - or perhaps not natural at all, but cultivated in an environment - a home - where his thoughts, alternately mutinous and self-pitying, were best kept far from his face. To survive would be to hide, and he immediately started conditioning his mind to hide whatever it needed to. His friend Narcissa had been an excellent help with that, being as she was a natural Occlumens with training from an early age. His Lordship was more than welcome to underestimate him and his strength. He was welcome to believe that his own mind was so clear and sharp that he saw reality exactly as it was, that nobody as small as Severus could pull at the threads it was woven from, distorting it, making it opaque where it might have been clear and clear where it ought to have been opaque.
Storycraft was, in his opinion, one of the most overlooked arts of war. And he needed a story, a good one, one that introduced a niggling suspicion in his Lordship that something terrible would happen to him if he ever tried to use Aveda Kadavera on Severus.
The idea came to him right away - that night, perhaps, or within a week of witnessing the first pointless death of so many.
The ultimate execution of the idea didn't come until much later, and it came in exchange for, ironically, the only thing he would have been willing to trade his life for.
Severus Snape was too clever and pessimistic to believe for a single moment that his Lordship wouldn't rise again. Interregnum had had its comforts, ensconced as he was at Hogwarts with Dumbledore, but he felt that his life couldn't truly begin until his Lordship was dead for good. Of course he didn't know yet that "dead for good" in this case meant killed many times over, and it was a good thing - if anything could have made him lose heart, it might have been that. He therefore greeted the reappearance of the Dark Lord with a combination of dread and relief.
He was glad to have an excuse to miss the Welcome Back party in the graveyard, which sounded unpleasant by all accounts, returning to his Lordship at Dumbledore's direction several hours later. He'd honed his groveling and self-effacement skills to near-perfection under his Other Lordship (how he had delighted in how much it would have rankled Dumbledore to be called that), and Dumbledore's insights regarding Tom Riddle and his Lordship's psychology prepared him well to become a shadow to Voldemort's radiant light - if Voldemort tried to look at him too directly, he'd disappear.
A devoted servant, aimless for all these years, lost and bereft without him. A faithful follower, biding his time, chafing under the other side until his real master returned. A serious scholar, researcher, academic, yearning to use his intellect to serve the real man in the equation. When his Lordship looked at Severus, he saw everything his Lordship hoped to see.
He waited until his Lordship asked.
How did this happen, Severus?
Severus understood perfectly well what had happened when Voldemort had been felled by a baby. Dumbledore was right. It was love, simple love, the love that he knew Lily to be capable of for her child.
Severus also knew damn well that you might as well try to explain to grasshoppers that winter was coming or to a lovesick girl that the bad boy would hurt her in the end as explain Lily Evans's love to Voldemort. Waste of breath.
"Sir, I do not fully understand the magic they must have used. I have turned up nothing reasonable regarding charms, potions, hexes even. What happened to you is almost unheard of."
How can a child have done this to me, Severus?
"There is a bit of my family lore that may be relevant, Sir. I thought it too obscure, merely an old witches' tale, but after so many attempts to explain it hit dead ends, I came back to it."
What lore? What did you find?
"Sir, there is a very old story in my family that some people are naturally endowed with immunity to the killing curse."
Impossible. Nobody has ever survived! It's impossible!
"I agree, sir, of course. Nobody in recent memory. But in my family, there is a story. I beg your patience while I tell it?"
Very well.
"Pierre Leprince is one of my oldest traceable ancestors. To hear it told, one day, he got into a fight in a market over a business deal gone wrong. He dealt in magical substances and had been accused of swindling many times, substituting black guillemot eggs for ashwinder eggs and suchlike. A customer was enraged that the potion he had prepared to save his child's life didn't work due to Leprince's deception, and he invited him outside for a duel. The story goes that the attacker had an accomplice who stunned Leprince, rendering him unable to cast any spell in his own defense; when the man hit him with Aveda Kadavera, it bounced back on the attacker and killed him instantly. And Leprince lived another 30 years, becoming a very powerful, respected wizard. And..." Severus let himself look fearful, doubtful, overcome.
And?
He lowered his voice. "And from that day forward, his eyes were nothing but the brightest blue."
What color had they been before?
"Black, my Lord," Severus whispered, trembling.
Severus's face displayed nothing but fear, but inwardly he noted with satisfaction that his Lordship looked floored.
He continued. "Of course we didn't believe it. Didn't believe anyone could survive. It's impossible, of course it is. And of course, the baby Potter's eyes were never black. If he were my son, and his eyes had been black and then changed at the curse, then perhaps it would make some sense." He let his voice tremble with apparent frustration. "But it still doesn't fit. I can't- I can't understand it."
The father... the father was pureblooded.
"Yes, my Lord."
From a very old family.
"Yes, my Lord."
Perhaps related to yours?
"Perhaps, my Lord. All wizarding families are related if you go far back enough. But the trait of being impervious to the killing curse... the baby mustn't have gotten it directly from either of his parents. I'm afraid as explanations go, it remains woefully incomplete."
Severus had done well to deliver exactly the message he wanted to, when his Lordship was paying his full attention. He had, 13 years prior, updated two books he expected Voldemort could easily get his hands on (one in each of the Black sisters' libraries) to include glancing mentions of this Pierre Leprince and "family lore." The traces of magic he had used would have faded significantly by this time, especially considering how diligently he used magic to dust the shelves and how the books he had placed them between had powerful magic of their own.
Severus's triumph also made this a dangerous moment that needed to be tempered heartily with equal parts flattery of his Lordship and self-flagellation. Because if Voldemort truly believed that Severus may be impervious to his killing curse, he'd need a very good reason not to order some hapless recruit to aim it at him to test it out. He might also potentially feel threatened by Severus, at the idea that Severus had a power that he didn't. Few things enraged him more. The tidbit about the wizard being made more powerful by the curse probably wasn't enough to make his Lordship fear what Severus might become - his Lordship fancied himself quite powerful. He needed to believe that Severus didn't believe the story himself, certainly not enough to be emboldened into ever challenging him.
So Severus let out a pitiful whimper and curved his back so that his forehead nearly touched the floor. "I'm sorry, my Lord. I'm so sorry that I do not have a sensible answer to what has happened. I'm so sorry to have failed you. Please, do to me what you will."
The bone-crushing torture he was expecting didn't come. His Lordship must be incredibly weak, indeed. As he slammed his forehead into the floor over and over, thinking he must look like an oversized house elf, it occurred to Severus that he might have a good shot at him, if he were only courageous enough to take it.
And the boy? What of the boy?
"He lives on, Sir, I am devastated to say. Dumbledore is using blood magic to keep him from us." Severus remained kneeling, bleeding forehead pressed to the floor. "I can only hope that I can continue to serve you; I am pledged to you and would love nothing more than to see you victorious in your quest."
Voldemort had ordered him back to Hogwarts, of course, with orders to keep doing what he had been doing. And you know what happened next.