Harry grinned and adjusted his goggles as he looked at the mouth of the cave Aragog had led him too. Just inside it, he could make out the skin of an enormous snake.

"This basilisk must be fucking huge," he muttered to himself as he checked his guns. For this particular job, he'd brought his magnum and, more importantly, his sniper rifle. From his bandoleer hung a frag grenade, a flash-bang, and two tear gas grenades, as well as extra armor-piercing, explosive, and incendiary rounds. The rifle itself was chambered with MK211 High-Explosive Armor-Piercing Incendiary (HEIAP) rounds, and the goggles he was wearing were enchanted to act as a one way mirror, protecting him from the basilisk's gaze attack even if he looked it in the eyes. This snake was going to fucking die.

Carefully, he snuck into the cave, his enchanted boots not making a sound. After a little while, the cave walls became smoother, the floor flatter. He observed these changes in passing, not paying them much attention. What did catch his attention was the gigantic archway with a large statue of a snake on either side. Cautiously, Harry drew a large bouncey ball from a pouch in his clothes and threw it into the room, allowing it to bounce for a little while. When nothing happened, he moved past the arch, summoning the ball to him and putting it back in its pouch. The tunnel opened up into a wide, high-ceilinged chamber. The room was dotted with tall pillars, with carvings of massive snakes coiled around them, and in the center of each wall was an archway identical to the one Harry had just entered. Looking around the room, Harry nodded in satisfaction- this would be an acceptable place to lay his ambush. He took out the bipod for his sniper rifle and attached it, then positioned the gun in a corner where he would have a view of all three of the archways the snake might come through. He then went to each of the four archways and used a sticking charm to string a few pieces of string across each one. Then he settled down behind the gun, pulling on his invisibility cloak. Then, when he was sure he was completely prepared, he pulled out his wand. Aiming at the center of the chamber, he conjured a large, smelly sheep and hit it with a stinging hex, causing it to run around and bleat excitedly. Whenever it tried to leave the chamber, the sheep would simply bounce off of the string and run in a different direction.

After about ten minutes, he saw movement in the arch opposite the entrance tunnel. He hit the sheep with another stinging hex, as it had started to calm down, and it began panicking again. Then it died. One second it was running around like a terrified sheep, the next, a huge, yellow, serpentine head erupted from the arch and snapped down on the animal. A long, scaled body followed the head, wrapping and coiling around the pillars as the snake moved throughout the chamber. Harry tried to line up a shot, but the basilisk was moving too much, too rapidly, too unpredictably for him to get a decent line on its head.

"I smell death," whispered a low, sibilant voice. The snake looked around, and its eyes fell on the corner Harry was hiding in. Had Harry been alive, sweat would have broken out on his forehead as the snake began moving toward him, weaving in and out of the pillars so rapidly that Harry couldn't take a shot.

Just as the enormous snake lunged forward, fangs reared, Harry rolled out of the way. Unfortunately, he was just a little too slow. One of the snake's tremendous fangs tore into his right leg, venom sizzling as it dissolved his flesh.

Harry roared in pain and drew a tear gas grenade from his bandoleer and pulled the pin, then shoved it into the snake's open mouth. The basilisk roared as the gas began entering its eyes, nose, and mouth, and pulled away from Harry. As quickly as he could, he staggered across the chamber to a different corner, then summoned his gun to him. The goggles he wore protected his eyes from the effects of the tear gas, and since he didn't breath, it didn't enter his lungs- he was completely immune to the poisonous fumes. The basilisk, however, was not so lucky. It screamed and thrashed in pain as the gas burned its eyes, mouth, and nose.

"What magic is this?" the basilisk cried as it thrashed wildly, "Who dares attack me?! I will tear your flesh from your bones! I will devour you whole! I will turn you to stone and dissolve your flesh with my venom!"

Harry laid down on his stomach again as the basilisk continued writhing in agony, and peered through the scope. As before, he couldn't get a bead on the snake's head properly. Now, though, he had time. The gas wouldn't dissipate for some time, and the effects would remain for a good half hour after that. The basilisk would likely be too intent on killing its attacker to leave the room, but it would be unable to find him- he was invisible, and the tear gas would keep it from smelling him. So he picked a spot near the snake's head and waited patiently. A few moments later, the serpent's wild thrashing brought it into his scope, and he fired. The HEIAP round left the chamber at four thousand feet per second, soaring across the room and struck the creature in the head. The Armor-Piercing Tungsten core bore through the basilisk's thick hide and skull. A moment later, the incendiary component ignited, causing the explosive component to explode, sending a shockwave through the snake's brain that turned it to jelly.

The body continued to writhe for a few moments as it tried to register what had just happened, but the beast was already dead. Harry, not knowing this, fired two more rounds into the monster's skull, then hurried out of the chamber through the door the basilisk had used.

He found himself in a long tunnel, which ended in a chamber identical to the one he'd just left, only without the archways. Another large basilisk skin was against a wall, but that was it.

Only now did he take notice that the scar on his forehead seemed to be smoking, and that there was a faint scream coming from the chamber he'd just left.

Shrugging, Harry inspected his leg. The basilisk's fang had pierced his left calf, piercing all the way through Harry's leg and narrowly missing the bone. No blood came from the wound, but a thick, black ichor was beginning to pool around the edges of the hole. The ichor smoked and sizzled as the orange basilisk venom ate away at it, but it kept flowing from the flesh surrounding the hole. Not knowing if he could be effected by the venom, Harry used his wand to cut away a fine layer of flesh from the wound, effectively removing any skin that had been in contact with the venom. That done, he transfigured the towel in his pack into a bandage and wrapped the wound, then left the room and went to explore the other two passageways. One of them led to a large series of underground chambers which didn't really have anything in them, and the other led to a small wooden doorway.

Harry took out his wand and checked the door for wards or traps, then opened it carefully, handgun at the ready, and threw his bouncy ball into the room again.

"You don't need to be so cautious, you know. You just killed a thousand year old basilisk. It's not like there's much in the universe that could hurt you. Come on in. It's been decades since I last had any company."

Harry opened the door the rest of the way.

Beyond it was a small, cozy room. One of the walls was lined with bookshelves full of hundreds of tiny little books, and one had two doors in it. Two large, cushy armchairs sat before an empty fireplace in the far wall, above which hung a portrait of a bald man with a pointed gray beard.

"Salazar Slytherin?" Harry asked, recognizing the man in the portrait immediately.

"Indeed," said the portrait. "Salazar Slytherin the Elder, at your service. Welcome to the Chamber of Secrets"

"Wait," Harry said, confused. "The Elder? You had a son? The stories don't mention that."

Slytherin sighed. "Yes, my last visitor, about a century ago, mentioned that. Most of what you've likely heard about me- the blood-supremacy and all that, is actually about my idiot son, Salazar the Younger. You see, he felt that, as my first-born, he should be at least as powerful as I am. Of course it doesn't work that way, but he refused to believe that. He got it into his head that he was weaker because I'd married a muggle, and her mundane blood diluted my magical. When I pointed out that witches and wizards could come from families with pure non-magical blood, he decided that muggle-borns were somehow 'stealing' the magic that rightfully belonged to him. Bloody moron was almost as insane as that 'voldemort' twat that forced Asclepius to attack all those children a few decades ago."

"You met Voldemort?" Harry asked.

"Not personally, no. I managed to maintain enough control over Asclepius, my basilisk, to keep the little prick out of here. See, Asclepius was supposed to obey my heir and protect the school. When the plumbing was installed about a century ago, some of the work unearthed an underground chamber. The headmaster at the time connected this area to that so that Asclepius would have direct access to the castle in event of an attack. A few decades later, some boy named Tom Riddle (the little idiot called himself 'Lord Voldermort. I suppose he thought it sounded impressive) found that chamber while Asclepius was there. He ordered Asclepius to start petrifying muggle-borns. Well, Asclepius was in a bind. She couldn't disobey my heir, but she couldn't harm the students. Eventually, she went insane and developed two personalities. One side was bloodthirsty and evil, like Riddle, her new master. The other side was devoted to the protection of the castle. Eventually, the evil side became the dominant personality, and the other side was crushed. Fortunately, the good side maintained enough control to keep Riddle out of the Chamber. If he'd had access to the knowledge in here, he could have done some serious damage to the wizarding world, and nobody could have stopped him."

Harry looked up at this. "Is there information in here that could be used against Voldemort?"

"Of course," replied Slytherin. "Powerful magic would be just as capable of working against him as it would be of working for him. There's no true 'dark' magic, you see. It all depends on how it's used. In my day, we knew that. From what that lad told me a century ago, modern wizards think that 'dark' magic somehow corrupts your soul or some shit like that. Idiots." Slytherin scoffed. "I will require a magical oath, however, that you won't use the knowledge I'm about to give you to harm innocents before I tell you how to access that information without killing yourself. You can do whatever you like to bastards like Voldemort- if he's still around and causing trouble, he almost certainly deserves whatever you can do to him. But I won't allow my library to be used for evil."

Harry nodded, and took out his wand. "I swear upon my life and upon my magic that I will not knowingly or willingly inflict undo harm upon innocents. So mote it be." Harry's wand glowed briefly, and Slytherin nodded.

"Very good. I suggest A Practical Application of the Dark Arts, to start with. It's toward the top left of the bookshelf."

"And how do I get it safely?" Harry asked.

"Oh, you don't need to do anything special. Just take it off the shelf. The shrinking spell will be temporarily negated as soon as you open it, and it'll shrink down again whenever it's closed."

Harry stared. "You were bluffing? I gave a magical oath for that information, and you were bluffing?"

Slytherin grinned. "Absolutely. I never bothered to put any security on this place besides a notice-me-not charm and Asclepius. I honestly didn't think it would be necessary, what with a basilisk protecting the area."

Harry fumed for a few moments at being tricked, then shrugged as reason caught up with him. It wasn't like he was ever going to hurt any innocents anyway. That issue resolved, Harry walked over to the bookshelf and started looking through it, picking out anything that looked helpful. In addition to the book Slytherin had suggested, he took A Guide to Combat Magickes, then, as a though occurred to him, he turned to Slytherin again.

"Do you know any way that he could have avoided dying when he was hit by a killing curse?" Harry asked.

Slytherin's eyes widened, and he began to swear viciously in several different languages, some of which Harry couldn't recognize.

Eventually, the ancient wizard calmed down enough for Harry to ask "What? What did he do?"

"He made a Horcrux," Slytherin responded. "It's some of the only magic in the world that's actually evil by nature. It requires the ritual killing of an innocent human being, usually a child, followed by harvesting and destroying the person's soul. When the soul is destroyed, the energy released is channeled into splitting your own soul in half and storing one half in a powerfully enchanted artifact. I don't know the rituals involved, and even if I did, I wouldn't tell you, even if you gave an oath not to use it. That knowledge needs to be destroyed. There are only three things I know of that can destroy a Horcrux- basilisk venom, fiendfyre, or having a dementor swallow the soul fragment in question."

Harry frowned. "I just killed what's probably the only basilisk in existence, I doubt I could control fiendfyre, and dementors always try to kiss me whenever they see me. I'm in trouble, aren't I?" he asked.

"Not necessarily," Slytherin responded. "I'd intended to save this for one of my heirs, but circumstances change. So, here goes." At that, the portrait swung forward, much like the portrait of the Fat Lady did, to reveal a small cubby. Inside was...

"A basilisk egg? You want me to hatch a basilisk? Are you insane?" Harry asked.

"You really don't have a choice, I'm afraid. If you can't control fiendfyre, your options are dementors or basilisk venom. If dementors truly attack you on sight, and since basilisk venom eats through pretty much everything, you'll have to have an actual basilisk. Besides, a basilisk makes a fantastic familiar, and the one in this egg is a male, so he won't have the gaze attack."

"Wait, male basilisks can't kill by sight?"

"You didn't know that?" Slytherin asked. "What are they teaching in Hogwarts these days?"

Harry scoffed. "Mostly how to turn teapots into turtles and when the latest goblin rebellion was, with a healthy dose of how incompetent we are at potions. But basilisks have been supposedly extinct for over seven hundred years, and breeding them yourself is punishable by life in Azkaban, so they're not exactly course material anyway."

"Basilisks are extinct?" Slytherin looked horrified. "Who keeps back the acromantulas, then?"

"What do basilisks have to do with acromantulas?" Harry asked.

"What do you mean, what do they have to do with acromantulas? Basilisks are the only thing they fear! Without basilisks to keep them in check, the acromantulas would kill everything. They're immune to most spells, they're vicious killers, and regard any other creature, even other acromantulas, as food!"

Harry frowned. "I don't know anything about basilisks keeping acromantulas in check," he said, "but the acromantulas in the forest don't seem to be like that. They've been at war with the centaurs for a few centuries, from the sound of it, but they don't really kill other creatures. Hell, I got them to agree to protect the centaurs in exchange for killing the basilisk that lived here."

"There are acromantulas here? In the Enchanted Forest? And Hogwarts hasn't sent in a force to wipe them out?"

"The Enchanted Forest?" Harry asked. "It's the Forbidden Forest now. And what do you want Hogwarts to do- send in a group of teachers? Even if they killed the acromantulas, they'd be slaughtered by vampires, lethifolds, or the other dark creatures that live in the forest. I'm pretty much the only one who can survive in these woods, and that's only because I can't be killed."

Slytherin looked aghast, then sighed. "Things have truly gone downhill, then," he said. "In my day, the forest was populated by creatures of the light, not the dark. The Enchanted Forest was one of the most beautiful places in all of Europe. That's why we built Hogwarts there. And the castle was more than just a school- it was the premier military instillation in the wizarding world. Why do you think it's built like that? It's a fortress- it has only one real entrance, with a half-dozen hidden exits, and dozens of secret passageways. It's got traps, weapons, armor, and wards to protect it. And you thought it was just a school? Who in their right minds would build a school like that?"

Harry looked slightly sheepish. "Well, I always figured that the lot of you were slightly mad," he responded.

"That's it. I'm coming out of this god-damned cave if it kills me. Again. The wizarding world needs to be fixed. But before I can come out, you need to kill Voldemort. If he's anything like he was when he was in school, he controls half the wizarding world by now. I'd be destroyed before I could do any good. And to kill Voldemort, you need a basilisk. Now come take this bloody egg. I'm tired of hanging open like this."

Against his better judgement, Harry stepped forward and put his hands into the cubby. When he reached into it, it felt as if he were reaching into a pool of warm water. He grabbed the egg from its stand and took it out, then closed Slytherin's portrait.

"Good," said the portrait. "Now, put the egg down and tap it with your wand. It'll want to bond right away, so have a name ready. And I suggest you transfigure a mouse for it to eat. He'll be hungry as soon as he hatches."

Harry considered for a few moments, then decided on a name he'd read in a book once.

He placed the egg on the ground and conjured a few mice, then tapped the egg with his wand as Slytherin had said. Instantly, a crack appeared where the tip of his wand had touched the egg, and began to spread across the shell. A few moments later, the egg erupted into scarlet flames and turned to ash. In the center of the ashes was a large yellow snake, roughly three feet lon with a red plume on its head. The snake looked Harry in the eyes, then was distracted by the mice scurrying across the floor. It quickly moved after the nearest one, sinking its fangs into the helpless rodent.

"Food," the snake said after the mouse stopped twitching. "Eat first. Bond later," this last was said with a glance towards Harry.

Harry nodded and replied in parsletounge, "Yes. Eat first. Then we will bond."

The snake nodded and unhinged its jaw to swallow the mouse. When it was done with its meal, it crawled lazily to Harry's feet, a noticeable bulge in its stomach.

"Pick him up and let him wrap around your wrist. Then tell him his name," Slytherin instructed.

Harry bent down to pick up the snake. When he reached toward the creature, it sniffed his hand.

"Why do you smell of death? Am I to be bonded to a corpse?" it asked.

"I am not a corpse, but under a curse. I am neither living nor dead, but my body is as of the dead," Harry responded. Slytherin's eyebrows raised at this, but he said nothing.

The baby basilisk gave Harry another sniff, then wrapped around his wrist.

"What is my name, master?" the basilisk hissed.

"Your name is Ahktar."

The snake considered this, then nodded once, opened its mouth, and sunk its fangs into Harry's wrist.

"Ow! What the fuck was that?" Harry asked as the snake withdrew its teeth.

"That was the bonding process," Slytherin responded. "Don't worry about being poisoned, he won't start developing poison for a few hours. Ahktar is now bound to you. Upon your death, his new master will be your chosen heir, so long as he is of your bloodline. Should your heir be of a different family, Ahktar will choose his new master, if he desires one."

Harry frowned. "I'm the last Potter. And I'm sterile."

"Something to do with that curse you mentioned?" Slytherin asked.

Harry nodded.

"Well, there's nothing for it. Train young Ahktar to be a good and honorable creature, and you won't need to worry about his choice of master when you die."

Harry thought about this, then shrugged. If Ahktar went bad, Harry could always kill him after Voldemort was taken care of. He wouldn't tell Slytherin that, though.

"So, what are the differences between a male and female basilisk?" Harry eventually asked as he stroked Ahktar's scales. The snake was... endearing, somehow.

"Well, a male's venom is far more potent, killing its victim almost instantly. In addition, the male doesn't have the gaze attack, like we discussed, but can turn invisible at will. That's... well, that's pretty much it."

Harry looked at the snake wrapped around his arm again and stroked its scales some more. If what Slytherin had said was true, he'd just gained a powerful ally.