As far as Harry knew, none of his friends said anything to anyone else about what had happened, but even so, the whole school knew by morning. Filch himself kept the event fresh in everyone's minds for several days after by haunting the scene of the crime and lunging out of secret passageways, accusing students who seemed "too happy" of being the perpetrators. Ron mentioned in passing that his sister Ginny, a first year, had been on the receiving end of one such accusation and burst into tears.

There was a lot more activity in the library now, which much of their group disliked for one reason or another, mostly because the amount of noise meant they could no longer hear each other when they spoke at a volume deemed acceptable by the librarian. Harry took to delivering Madam Pince-level glares at anyone within range, green eyes flashing. Still, it was unavoidable that they would overhear…

Hogwarts was founded some time before 1000 AD by Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin. They built the castle that housed the school and brought in students who showed signs of magic in order to teach them how to use their gifts. Yet a rift soon developed between Slytherin and the others, over which students should be taught; Slytherin felt that their arts should be restricted to all- or mostly-magical families, whereas the others argued that anyone with magical talent should be welcomed and educated.

In the end, Slytherin left Hogwarts, but not before building the Chamber of Secrets somewhere in the school and putting a monster inside – a monster only his Heir could control and use to purge the school of those "unworthy" to study magic.

Or so the rumors said.

Harry raised an eyebrow as his friends debated what kind of "monster" Slytherin could have left, going through increasingly ridiculous possibilities until he couldn't help but roll his eyes. "It should be obvious."

"What?"

"Slytherin and his descendants were all able to talk to snakes, right? I've been reading up, and it's not a common ability. His monster has to be some kind of snake, something only he and his Heirs could speak to and control."

Everyone blinked, then realized he was right. "How did you learn that?" Hermione asked, leaning in eagerly.

"I was looking up information about witches and wizards who could talk to animals without casting spells or brewing potions or the like, and Slytherin came up. Him and Herpo the Foul and – Voldemort." He stumbled over the name for a second; he had been about to say 'the Dark Lord.'

That made them all blanch, all except Draco. "Don't say his name," Ron hissed.

"It's a name, Ron," Harry said, rolling his eyes again, "It's not like saying 'Voldemort is going to conjure him up any more than saying 'oak tree' will make our table turn into one."

And of course, right as he finished speaking he sensed Voldemort's presence. Just a brief blip, barely long enough to register, but it was enough. Harry frowned briefly, then forged on, figuring now was as good a time as any, "I wanted to know more about the ability to talk to animals, anyway, if it was common, the usual animals talked to, etcetera."

Draco snorted. "'Common?'" he repeated, "Try 'the number of people in history able to speak to animals without outside help couldn't fill Diagon Alley.' Why, can you?"

Harry nodded. "Snakes. But I can't for the life of me figure out where it came from – my family's not related to any of the founders, much less Slytherins. My mom was muggleborn, and most of the Potters were Gryffindors with the odd Ravenclaw and one – one – Slytherin. There's no history of Parseltongue in the family genealogies I've had time to look through. I just don't understand where it could have come from."

"How long have you had it?" Hermione asked.

"As long as I can remember. I used to talk to garden snakes back when my aunt and uncle were still alive, and now my parents' house backs up to a small wood. Some snakes live there, and I let them into the house to eat the mice and rats. Some of them are actually quite sweet and bring me little things they think I might find interesting. – But that's not the point." He flapped a hand. "I heard a snake – or at least something I can understand with Parseltongue – inside the walls not too long before we came upon Mrs Norris."

"Inside the walls?" Neville repeated incredulously, eyebrows nearly climbing into his hairline.

"I know, right? But there was no one but us in the hall, and nothing invisible as far as I could tell, so that was the only conclusion I could draw."

Of course, that started Ron and Draco arguing about if ghost snakes were a thing that existed, much to Harry's mixed amusement and exasperation. They were still arguing about it when they all broke to go to class, making the young Potter heir shake his head. "Those two," he sighed to Neville as they walked down to the greenhouses, "Sometimes they're mortal enemies, sometimes they're thick as thieves."

"And all on a schedule only they seem to know," Neville added, making Harry snort.

That weekend, they all returned to the scene of the crime to see if there were any clues left behind from their "ghost snake." They found scorch marks and spiders fleeing the castle like it was going out of style, but got nothing from a ghost named Moaning Myrtle who lived in the bathroom practically right next door. None of them felt any real urgency to continue pursuing the possibilities-

Until a student was attacked. Colin Creevey, a first-year Gryffindor. Harry pulled out the invisibility cloak and carefully sneaked into the hospital wing to see him. He, too, had been petrified, and his hands were frozen up in front of his face like he had been holding something – the wreckage of a camera, now on his bedside table.

Draco wrote his father the very next day, asking for anything he could tell them about the Chamber and the snake-creature within; there were more than four dozen different creatures it could have been, though none of them seemed to petrify people the way this one did. Gorgons turned people to stone, but that was the closest they could find.

Not too long after, a Dueling Club started up with the intention of teaching the students how to protect themselves in combat. And, of course, it was Lockhart who started it, assisted by Professor Snape, who looked even more sour than usual. Their mock-duel was over in a single spell, the potions master downing the other wizard with the Disarming Charm. Of course, that was the only spell the demonstrated before breaking everyone up into pairs to practice their skills.

Harry wound up getting paired with an older Slytherin, one who didn't like him very much if her glare and sneer were anything to go by. When Lockhart gave the signal to begin, she proved it, snarling, "Serpensortia!" and launching an adder at his face. He shot a Disarming Charm back, only to have the older student shout, "Protego!" and shield herself from it. While she was distracted, he flicked a nonverbal levitation charm at her feet, yanking them out from under her.

Then he called to the adder, "Hey, snake! I don't know your name, but you need to come over here or you're gonna get hurt!"

"Speaker…" the adder hissed and slithered over to him, letting him scoop it up and tuck it into the sleeve of his robes. It coiled around his arm and held tight, though not tight enough to cut off circulation.

The Slytherin snarled at him from the ground and launched two more spells at him. He cried, "Protego!", hoping that the apparent shield charm would block-

It did, although the other spells sent him skidding back a bit. He kept his feet, however, and was about to return fire when Snape called the match.

The adder made it the rest of the way up his arm and over his shoulder to peek out from the collar of his robes, tongue flickering. "Who are these two-leggers, Speaker?" it asked, "Why have they gathered in such numbers? Can I eat them?"

"The older ones are teaching us to defend ourselves," Harry answered quietly, careful not to make any gestures that could be construed as threatening – or any gestures at all. "We aren't born knowing how to fight – we have to learn."

"How strange," the serpent hissed.

"Mr Potter."

Harry looked up. Snape had his wand out but lowered, and was eyeing the adder. "I'm going to have to send that snake back, Mr Potter. I'm afraid it cannot stay."

The Ravenclaw told the serpent and laughed at its response. "He says he hopes it's a better trip than the one that brought him here."

That earned the tiniest hint of a smile from the potions master, and a ripple of snickers from the students listening in. The adder slithered out from his robes and down into his hands, and vanished with a flick of the professor's wand. "Have you always been able to talk to snakes?" the man asked.

Control the narrative, Harry. "For as long as I can remember, but no idea where it came from – neither of my parents are related to any of the founders as far as I can tell, and almost all the Potters were Gryffindors. If we were related to anyone, it would probably be him." He pitched his voice carefully, loud enough for others to hear but not enough to seem intentional.

It was all over the school by the next day. Most people seemed to believe him – some even calling him "Gryffindor's Heir" – which also gave Zacharias Smith five minutes of fame as the legitimate "Heir of Hufflepuff." Still, there were whispers in corners that since his father had been a pureblood, he had to be related in some way to all the other pureblood families, including Slytherin.

Harry ignored them for the most part, except where they were unavoidably loud or up-front about it. Quite rude… but inconsequential in the grand scheme of things. He ignored it-

Until Justin Finch-Fletchley turned up petrified, along with a ghost, "Nearly-Headless Nick" of Gryffindor. Finch-Fletchley may have been one of the students badmouthing him, but Harry certainly hadn't set Slytherin's monster on him. He did get sent to the headmaster, though, but had nothing to add that wasn't already circulating through the rumor mill.

(He barely remembered to avoid the headmaster's gaze, but he still remembered.)

On his way out of the office, he bumped into the groundskeeper, who had a dead rooster swinging from one massive fist. He inclined his head to the man, who looked tickled pink at being acknowledged, and continued on his way, meeting up with his friends on their way down for dinner.

They heard Filch shouting from a long way off. The man went storming past them, snarling about "adding to his workload" and "flooding the halls for the past fifty years" and "telling the headmaster we need an exorcist!"

They soon saw what he had been ranting about – the first floor corridor was flooded again, same as it had been the night Mrs Norris was attacked. The letters gleamed bright as ever on the wall in the light of the torches, but even the crackling of the fire couldn't cover up the sound of Myrtle sobbing harder than usual in her bathroom.

Harry frowned and focused – and felt Voldemort's presence. It was close, intense- closer than it had ever been. And there was really only one place…

He pushed open the door to the girls' bathroom and called, "Myrtle? What's the matter?"

There was a wet sniffle from one of the stalls. "Who is it? Come to throw another book at me?"

"It's Harry Potter; we met on Halloween." He waded over to her stall and nudged the door open. "Why would I throw a book at you?"

"Don't ask me," the ghost snapped, emerging from the toilet in yet another wave of water, "Here I am, minding my own business, and someone thinks it's funny to throw a book at me!"

"Well I don't think it's funny," said Harry, "Do you want me to take it? Where did it go?"

"By all means! It's over there, it got washed out." She pointed.

Under the central sink was a thin black book sitting in about an inch of water. Harry picked it up – and froze for an instant, noticeable only to those who knew him very well.

The book radiated Voldemort's presence for those who knew how to look, but it felt… odd, in a way Harry couldn't yet explain.

"Take care, Myrtle," he called back to her, "I'll see if I can find who this belongs to and throw it at their head for you."

He barely heard her response, already flipping through the pages. The book – the journal – was soaked with water and power, with T M Riddle in faded gold lettering on the back.

He tucked it away during dinner, not wanting his friends to be suspicious when really all he wanted to do was study and poke and prod the book. What had the Dark Lord done, to seal himself inside a book? Or get sealed in one?

After everything wrapped up for the evening, Harry climbed into bed and drew his hangings around, casting a silencing charm just in case. Then he examined the book in his hands, turning it in all directions and peering as closely as he could at it before finally cracking it open. Every page was labeled with the "week of", but there was absolutely nothing in it, not even blurred ink from its soaking.

Harry frowned, and reached for ink and a quill.

Voldemort?

Nothing.

I know it's you. I can feel your presence. How did you get inside a book? Are you possessing it somehow, like with Quirrell?

Then, in a different hand, Who is this?

Harry blinked, because what. Had Voldemort lost all his memories when he left Quirrell? This is Harry Potter. Don't you remember?

I'm afraid not. This is just a memory of me at sixteen, locked inside a diary. I haven't interacted with my current self in a long time.

Oh, I'm sorry.

It's all right, you didn't know. But – you've encountered my current self?

Last year, yes. You… weren't looking to good. Living in the back of a professor's head, no body of your own.

I see. Is there anything else?

Apparently there was a prophecy made about us, that said I was to be your downfall. I don't see how, seeing as I wasn't even born when it was made, but something happened the night you came for me, and you lost your body.

How?

I don't know. Dumbledore says it was because my mother sacrificed herself to protect me, but that sounds like a line to me. How many mothers gave their lives to protect their families during the war? How many sacrificed themselves so that their children might live? I've never heard of this 'sacrificial protection' saving anyone before. But there's more, Harry went on, Neither you nor I know the full prophecy, so in the interest of neither of us experiencing a repeat of what happened that night, we have a ceasefire. At least until we learn the full text and decide what to do about it.

It must have been delivered in full to someone. The Ministry should have a copy of their memory in the Hall of Prophecy, part of the Department of Mysteries. And what war are you referring to?

The last wizarding war. Your current self started it, for reasons I don't know.

Then what do you – this is tedious. Let me…

There was a jerk, and Harry found himself falling forward into the diary, which opened up to welcome him. It was like falling into a warm bath on a cold winter's day, his whole body relaxing into the magic that surrounded him. When he landed, he was in what must have been the Slytherin Common Room, circa 1940. There was only one other occupant, who could only be Voldemort at sixteen, still young and handsome with dark hair and pale eyes.

"Come here," said Voldemort, gesturing him over, "I am not as powerful or skilled as my current self, but I still can…" Harry walked over to stand in front of him and, when the Dark Lord tilted his head up, looked into his eyes.

In his mind's eye, the events of his life started playing – the blurred memories of infancy, the flash of green light that took his mother ("No, not Harry! Please!"), the – flight? – that brought him to the Dursleys.

The Dursleys. Voldemort hissed profanities in Parseltongue when he saw the things they had done to him, forcing Harry to clean before he even understood dirtiness, cook when he could barely reach the stove. Harry Hunting. The smacks and hits when he failed or fumbled or got higher grades than Dudley, or whenever anything unnatural happened.

Their deaths, and the appearance of his new family. His much-better life with them, living and growing and learning in peace, wandering unafraid as the child of High Wendigos.

Then, The Letter. The goblins, the adoption, the Malfoys, the Sorting, his first year.

The other Voldemort. The deal they struck. His warning to Lucius, the events of the summer, and his second year to date.

This Voldemort withdrew, frowning. "Even accounting for the inevitable bias of the 'light,' this is not what I had in mind," he muttered, more to himself than Harry, "Such open violence – the deaths of so many magical families – what happened? Where is our Slytherin cunning? Where are all of our so carefully laid plans?"

Harry shrugged. "There's too much I don't know to be able to answer that. Although… are you – stronger, than he is?"

Because that was it. That was what was odd. Since he – or his perception – was "inside" the diary, he could feel Voldemort all around him. His presence felt more powerful, concentrated – more intense – than the one that had passed through him at the end of last year. Harry was pretty sure he was correct in that guess, but he didn't understand how a "memory" of Voldemort was stronger than the real thing.

From the look on the teen's face, he didn't either

Until he did.

"No," he murmured to himself, "That can't be it. That can't be it! There has to be some other explanation-!" But his mind seemed to be caught on whatever he'd thought of, because his frown deepened until his whole body was frowning. "Harry, I need you to check something for me so I can confirm a theory. Do you have a way of getting to the seventh floor unseen? Do you know the Disillusionment Charm?"

"I have an invisibility cloak." The teen had skimmed over that part, marking it as sentimental and unimportant.

"Good, good!" Voldemort taught him a spell to muffle the sounds of his feet, then continued, "I need you to go to the seventh floor, the left-hand corridor. Find the tapestry of the wizard trying to teach trolls ballet. On the opposite side of the hall is a stretch of blank wall; walk past it three times, thinking, 'I need the Room of Hidden Things,' and a door will appear. Go in, and look for my presence. My current self should have concealed another – memory, there. I need to check…"

"Seventh floor, left side, ballet trolls, Room of Hidden Things. Got it." Harry nodded.

The diary spat him back out, and he briefly missed being inside it before digging for his cloak. He cast the muffling spell the Dark Lord taught him, then pulled the cloak on.

With the diary tucked under his arm, wand in hand, and a pen in his pocket, he slipped out of the dormitory and headed up the stairs to the seventh floor, moving slowly and carefully to avoid teachers and prefects. He found the tapestry where Voldemort said it would be, walked in front of the blank wall – and a door appeared, opening into the messiest room he had ever seen, and he had lived with Dudley. Piles and piles and piles of junk – broken desks, chairs, and other furniture; ripped books; old clothing; cauldrons with potion caked on; bent telescopes; a scorched set of runes the size of Galleons; the list went on and on and on.

And somewhere in the disaster, Harry sensed the Dark Lord's presence. He scrawled as much in the diary – I feel you; give me a minute – and started wading through all the stuff, briefly grateful that tomorrow was Saturday. It felt like it took hours, but at last Harry's hand closed on some kind of tiara. A jolt went up his spine, same as with the diary, and he grinned.

I've got it!

What is it? What does it look like?

Some kind of tiara. Then he read the inscription on it. Is this Ravenclaw's diadem?

So we did find it, then. I wondered if we would. Touch it to the diary.

Harry did so, but he already knew. The "memory" (which, he called bullshit on that so hard) in the diadem was weaker than the one in the diary. The current Voldemort was weaker still.

A ripple passed over both objects, and the diadem whistled a little, then settled.

I did not anticipate this.

Is there anything else you want me to grab/think I should grab, or can I head back?

No, you can go. …Thank you.

You're very welcome.