Harry glared at Malfoy, furious that not only had he allowed himself to be caught in such a situation against better counsel, but that the spoiled Slytherin brat was here to have his fun. Even as lightning fizzled in his hands, however, he knew there was nothing to be done. He'd lost this round. And more footsteps could be heard.

"What's going on here? What's going on?"

Attracted no doubt by Malfoy's shout, Argus Filch came shouldering his way through the crowd. Then he saw Mrs Norris and fell back, clutching his face in horror.

"My cat! My cat! What's happened to Mrs Norris?" he shrieked.

And his popping eyes fell on Harry.

"You!" he screeched. "You! You've murdered my cat!"

Harry backed off in the face of the spitting, raving caretaker, his hands up and open, entreating the man to return to his senses. Ron took Harry by the shoulder, seemingly moving to defend him, but before the situation could escalate...

"Argus!"

Dumbledore had arrived on the scene, followed by a number of other teachers. In seconds, he had swept past and detached Mrs Norris from the torch bracket.

"Come with me, Argus," he said to Filch. "You, too, young Gryffindors... Miss Lovegood."

Lockhart stepped forward eagerly.

"My office is nearest, Headmaster – just upstairs. Please feel free –"

"Thank you, Gilderoy," said Dumbledore.

The silent crowd parted to let them pass. Lockhart, looking excited and important, hurried after Dumbledore; so did Professors McGonagall and Snape.

As they entered Lockhart's darkened office there was a flurry of movement across the walls; Harry saw several of the Lockharts in the pictures dodging out of sight, their hair in rollers. Ron was distracted by this even among the furor surrounding Mrs Norris. Seeing the disbelieving expression on his face, Harry gestured to him to wait, not wanting more attention drawn to them.

Dumbledore was examining the cat on the polished surface of Lockhart's desk. To Harry she seemed to be as dead as the dodo, but the caretaker's pet was curiously frozen. Perhaps it was rigor mortis?

The tip of Dumbledore's long, crooked nose was barely an inch from Mrs Norris's fur. He was looking at her closely through his half-moon spectacles, his long fingers gently prodding and poking. Professor McGonagall was bent almost as close, her eyes narrowed. Snape loomed behind them, half in shadow, wearing a most peculiar expression. It was as though he was trying hard not to smile. And Lockhart was hovering around all of them, making suggestions the likes of which Harry could not possibly speak to their veracity. Professor McGonagall surely could, however, and from her expression of restrained contempt Harry felt assured in his presumptions.

The man was a complete tosspot.

While he made wild claims about Transmogrifian Tortures and his proficiency with counter-curses, Argus Filch was slumped in a chair by the desk, unable to look at Mrs Norris, his face in his hands. His dry, racking sobs punctuated each of Lockhart's self-important remarks. Much as he detested Filch, Harry couldn't help feeling a bit sorry for him, though not nearly as sorry as he felt for himself. If Dumbledore believed Filch, he would be expelled for sure.

Professor Dumbledore was now muttering strange words under his breath and tapping Mrs Norris with his wand but nothing happened: She continued to look as though she had been recently stuffed.

Their illustrious professor of Defence was utterly oblivious as to the headmaster's progress. Harry felt his jaw clenching tighter as Lockhart began recounting a tale from his books as though this were a sales pitch rather than what was looking more and more like a forensic investigation. When he saw Hermione listening to the man with rapt attention, he felt like jumping in with the apparently sympathetic Ron and Neville and giving the professor a good kicking.

Luckily, before the boys could get too worked up, Professor Dumbledore straightened up.

"She's not dead, Argus," he said softly.

Lockhart stopped abruptly in the middle of counting the number of murders he had prevented.

"Not dead?" choked Filch, looking through his fingers at Mrs Norris. "But why's she all – all stiff and frozen?"

"She has been Petrified," said Dumbledore ("Ah! I thought so!" said Lockhart). "But how, I cannot say..."

"Ask him!" shrieked Filch, turning his blotched and tearstained face to Harry.

"No second year could have done this," said Dumbledore firmly. "It would take Dark Magic of the most advanced –"

"He did it, he did it!" Filch spat, his pouchy face purpling. "You saw what he wrote on the wall! He found – in my office – he knows I'm a – I'm a –" Filch's face worked horribly. "He knows I'm a Squib!" he finished.

"What on…" Harry began, utterly thrown by the notion that Filch's magical prowess could be at all relevant. "I haven't done anything to your cat. Why should your being a Squib or not mean anything to me?"

"You students are all the same!" snarled Filch. "Ungrateful little whelps! I bet you thought it would be mighty funny, eh? Who'll be laughing when you're rotting in the dungeons, eh?!"

Professor Dumbledore put a hand on Filch as he tried to leap at Harry, muttering something to the man under his breath. When he was done, Filch didn't so much as look at Harry, all but dissolving into tears as he backed away towards the wall.

"If I might speak, Headmaster," said Snape from the shadows.

Harry's sense of foreboding increased. He was sure that nothing Snape had to say was going to do him any good.

"Potter and his friends may have simply been in the wrong place at the wrong time," Snape said, a slight sneer curling his mouth as though he doubted it. "But we do have a set of suspicious circumstances here. Why was he in the upstairs corridor at all? Why wasn't he at the Halloween feast?"

Harry, Ron, Neville and Hermione all launched into an explanation about the deathday party. Luna looked at the fireplace with mild curiosity, while Professor Dumbledore seemed to regard Luna in a similar manner.

"... there were hundreds of ghosts, they'll tell you we were there –"

"But why not join the feast afterward?" said Snape, his black eyes glittering in the candlelight. "Why go up to that corridor?"

Ron and Hermione looked at Harry.

"Because – because –" Harry said, his heart thumping very fast. Something told him it would sound very far-fetched if he told them he had been led there by a bodiless voice no one but he could hear. "Because we were tired and wanted to go to bed."

"Without any supper?" said Snape, a triumphant smile flickering across his gaunt face. "I didn't think ghosts provided food fit for living people at their parties."

"We were planning on asking the twins to get us some food," said Neville.

Snape turned a dark look on the boy, who trembled slightly. Still, his Gryffindor strength held through. Neville met Snape's cold stare with a glorious defiance that made Harry feel truly proud.

"And where is the young Miss Weasley," said Snape, "who normally seems attached to you as if by elastic cord, Potter?"

"Throwing up in a toilet somewhere, Professor Snape," said Harry. "As you said, the dead don't have food fit for the living."

"I suggest, Headmaster, that Potter is not being entirely truthful," he said. "It might be a good idea if he were deprived of certain privileges until he is ready to tell us the whole story. I personally feel he should be taken off the Gryffindor Quidditch team until he is ready to be honest."

"Really, Severus," said Professor McGonagall sharply, "I see no reason to stop the boy playing Quidditch. This cat wasn't hit over the head with a broomstick. There is no evidence at all that Potter has done anything wrong."

Dumbledore was giving Harry a searching look. His twinkling light-blue gaze made Harry feel as though he were being radiographed. "Innocent until proven guilty, Severus," he said firmly.

Snape looked furious.

So did Filch. "My cat has been Petrified!" he shrieked, his eyes red and wet. "I want to see some punishment!"

"We will be able to cure her, Argus," said Dumbledore patiently. "Professor Sprout recently managed to procure some Mandrakes. As soon as they have reached their full size, I will have a potion made that will revive Mrs. Norris."

"I'll make it," Lockhart butted in. "I must have done it a hundred times. I could whip up a Mandrake Restorative Draught in my sleep –"

"Excuse me," said Snape icily. "But I believe I am the Potions master at this school."

There was a very awkward pause.

"You may go," Dumbledore said to the assembled students.

They went, as quickly as they could without actually running. When they were a floor up from Lockhart's office, they turned into an empty classroom and closed the door quietly behind them.

Harry squinted at his friends' darkened faces. "D'you think I should have told them about that voice I heard?"

"No," said Ron, without hesitation. "Hearing voices no one else can hear isn't a good sign, even in the wizarding world."

Something in Ron's voice made Harry ask, "You do believe me, don't you?"

"'Course I do," said Ron quickly. "But – you must admit it's weird..."

"I know it's weird," said Harry. "The whole thing's weird. What was that writing on the wall about? 'The Chamber Has Been Opened'... What's that supposed to mean?"

"You know, it rings a sort of bell," said Ron slowly. "I think someone told me a story about a secret chamber at Hogwarts once... might've been Bill..."

"It's a horror," said Neville. "A secret chamber Slytherin built before he left, holding a monster that waits to cleanse the school of all those who Slytherin deemed unworthy."

"That seems a bit extreme!" said Hermione. "These were children he'd looked after and taught for a good part of his life."

"It's a story, Hermione," said Neville. "Maybe he didn't intend to actually kill them. Maybe it's all made up."

"If it is, someone's planning to murder all the unworthy in Slytherin's name," Hermione murmured. "All the... Muggleborn..."

"You'll be fine, Hermione," said Neville.

"Yeah, we'll sort this out," said Ron.

"Nobody else is getting hurt if I can help it," said Harry.

"Thanks guys," said Hermione quietly. "We should look for Ginny."

"I think she's looking for us," said Harry.

At that moment, the door opened and in came Ginny, her bag clutched tightly to her side. "What's going on? What happened? I heard a bit of a commotion..."

"How did you find us?" said Hermione, frowning.

"Point me, Harry," said Ginny, her wand floating up in the air from her open palm and emitting its customary golden light. Harry's surprise and pride that she had planned an answer to that question drained as he noticed how pale she looked. "Now tell me what the hell happened."

"Mrs Norris got Petrified," said Harry.

Ginny trembled visibly. "You mean...?"

"Yeah, the long-term magical kind," said Neville. "They're sorting out a Mandrake draft, but I'd guess a few months before that's ready."

"Why don't they just order some in?" said Hermione. "Surely you can buy it?"

"Not cheaply," Neville shrugged.

Meanwhile, Ginny still looked utterly horrified. And to Harry's seventh sense, she was practically made of shock and anxiety.

"Ginny, Mrs Norris will be fine," said Hermione in a comforting tone, though she could not hide her bewilderment.

"I... Yeah," Ginny agreed. "So, what should we do? I'm pretty tired."

"Ask the twins for food," Ron said firmly.

None of them could find fault with this, so they hurried up towards the common room. Harry soon found himself losing interest in Ginny's state of mind, the ache of his empty stomach taking centre stage.

"So what was Filch on about back there?" said Neville as they closed on the Grand Staircase.

Ron snorted. "I'd forgotten about that. Explains a lot doesn't it?"

"He's bitter about being born without magic," said Neville.

"It seems rather cruel of the professors to have him keep the castle in order without magic," Hermione frowned.

"He's not the cleaner," said Neville. "He's just in charge of making sure everything that needs to be done gets done."

"So why's he always cleaning?" said Hermione.

"Something to complain about?" Harry shrugged. "I don't know why he doesn't quit."

"Yes you do," said Luna.

"Yeah," Harry agreed, "he enjoys having something to complain about."

"Oh look, people are still outside," said Hermione.

Indeed, the Fat Lady's portrait was swung wide open as the legion of satisfied, yet unnerved students poured in. They followed after them, finding their targets ready and waiting.

"So," said Fred.

"What kind of trouble..." said George.

"Have you lot stirred up this term?" said Fred.

"The cat was Petrified," said Ron.

"Blimey," said Fred.

"That's not one you'll hear every day," said George.

"I'll be right back," said Ginny, rushing past her brothers and up the dormitory stairs.

"Guys, we're starving," said Ron.

"Get us some food and we'll tell you everything," said Harry.

"Hey Luna," said George.

"This is the wrong common room, by the way," said Fred.

Luna opened her mouth to answer, but Harry cut across. "Food."

"Fine, fine, our curiosity shall wait," said George.

"Bring a lot!" Neville called to their retreating backs. "Ron hasn't eaten since half one!"

"Hey, you alright?" said Dean.

Seamus frowned. "That was kinda creepy down there."

"Somebody Petrified Mrs Norris," said Hermione. "Nobody knows who or how."

Seamus's jaw dropped. "You're joking..."

By the time the twins returned, the whole common room was buzzing. People who'd gone to bed early had come back down to see what all the fuss was about.

Ginny had emerged from the girls' dormitories looking a little healthier, but little happier than when she'd gone up. Neville expressed concern that was brushed off before he could finish speaking; nobody mentioned anything after that.

"This way, midgets," said Fred, his head emerging from the portrait hole.

They followed the twins to an abandoned classroom. On a solitary clean table in the middle, the twins had provided enough pork chops, potatoes and buttered vegetables to feed a small village. Their rumbling, growling stomachs already had all the encouragement they needed without the sizeable chocolate fudge cake that made their mouths flood at merely the smells.

"So," said Fred, as everyone but Ron returned to a sociable rate of face-stuffing.

"What've you got for us?" said George.

Harry shared a look with the others (apart from Ron). "We were coming back from Nearly Headless Nick's deathday party..."

Five minutes later, the twins were shaking their heads.

"You've had a rough evening, guys," said George.

"That voice..." Fred muttered.

"Creepy," said George.

"Weird," said Fred.

"Probably good you didn't mention it to the professors," said George.

"But if anyone could've explained it..." said Fred.

"It's Dumbledore," George sighed.

"I don't want him to think I'm mad!" said Harry.

George nodded, chewing contemplatively on some fudge. "But if that voice was serious..."

"And poor Mrs Norris will vouch for it," said Fred.

Ginny, who'd turned pale again through the retelling of the story, began to tremble. Harry took her hand, and she looked up at him with fear in her eyes.

'We've fought off Voldemort,' said Harry. 'We'll be okay.'

Ginny said nothing, and Harry understood what was left unspoken. Their safety was all well and good. But who was next, after Mrs Norris?

"We might have bigger problems soon," said Neville. "The professors saw the writing on the wall. They'll know about the Chamber of Secrets. If someone with the power and the will to start Petrifying is doing it in the name of Slytherin and his Chamber, the school is in big trouble."

"So you think it'll get shut down?" said Hermione.

"If this happens to a student?" said Harry. "I hope so."

For a few days, the school could talk of little else but the attack on Mrs. Norris. Filch kept it fresh in everyone's minds by pacing the spot where she had been attacked, as though he thought the attacker might come back. Harry had seen him scrubbing the message on the wall with Mrs Skower's All-Purpose Magical Mess Remover, but to no effect; the words still gleamed as brightly as ever on the stone. When Filch wasn't guarding the scene of the crime, he was skulking red-eyed through the corridors, lunging out at unsuspecting students and trying to put them in detention for things like "breathing loudly" and "looking happy."

Ginny, who had seemed rather affected on the night itself, was slowly recovering to her prior, abnormally reclusive self. Though she was fond of animals, and cats in particular, Harry was sure there was more to it than that. And yet, he couldn't help but feel that pursuing the issue wasn't really worth it. He wasn't the only one who had noticed, however, and it wasn't just Luna who was being brought down by Ginny's low mood anymore.

The attack had also had an effect on Hermione. It was quite usual for Hermione to spend a lot of time reading, but she was now doing almost nothing else. Ever since Neville's mention of the Chamber of Secrets, she'd been working feverishly to learn more of the tale, without a shred of success. Harry also suspected it was part of an effort to spend less time with the new Ginny, but he was wise enough not to accuse her. In fact, he rather sympathised. The negative mess of emotions Harry was washed with whenever he touched Ginny, let alone kissed her (not that there had been much of that lately), was really starting to work at him. He'd even started trying to stifle their bond.

One particularly poor Tuesday morning, Harry had been held back in Potions, where Snape had made him stay behind to scrape tubeworms off the desks. After a hurried lunch, he went upstairs to meet Neville in the library, and saw Justin Finch-Fletchley, the Hufflepuff boy from Herbology, coming towards him. Harry had just opened his mouth to say hello when Justin caught sight of him, turned abruptly, and sped off in the opposite direction.

Harry found Neville at the back of the library, measuring his History of Magic homework. Professor Binns had asked for a three foot long composition on 'The Medieval Assembly of European Wizards'.

"An inch over," said Neville with a dignified level of satisfaction. "Hermione's essay is nearly as tall as me..."

"Of course," Harry grinned, grabbing the tape measure and unrolling his own homework. "Where is she?"

"Somewhere over there," said Neville, pointing along the shelves. "She's looking for another book. Sometimes I wonder why she even bothers attending classes. And then I remember..."

"She's Hermione," Harry snorted. "Do you think this is another Chamber hunt?"

"Probably," Neville shrugged. "There's no discouraging her. I even showed her the letter from my gran telling me all she remembered of it."

Finding his own essay comfortably over requirements, Harry told Neville about Justin Finch-Fletchley running away from him.

"Oh," said Neville, putting his parchment away and turning to face Harry. "That is a bit odd. You don't think he thinks you're –"

Hermione emerged from between the bookshelves. She looked a particular kind of irritable that made them both shut their mouths and sit rather still.

"All the copies of Hogwarts: A History have been taken out," she said, sitting down next to Neville. "And there's a two-week waiting list. I wish I hadn't left my copy at home, but I couldn't fit it in my trunk with all the Lockhart books."

"Everyone's thinking the same as you," Neville sighed.

"Apparently," said Hermione. "This is so infuriating."

"Not knowing?" said Neville. "Or feeling like you don't know?"

Hermione looked at him contemplatively for a moment. "I don't know."

And then Hermione's lips curled upwards, and she rolled her eyes, looking away.

"So I heard your essay is taller than Nev," Harry grinned.

They arrived at the History of Magic classroom with slowly dampening spirits at the prospect of an hour with the endlessly droning ghost. By five minutes in, Harry was settling into a depressed stupor. He was just dropping off when he heard a faint rustling to his right. Suddenly curious as to whether Hermione had finally succumbed to the soporific power of Professor Binns' voice, Harry turned to look at her.

Hermione had raised her hand.

The gravity of such a moment was not lost on Harry, and he shook off his weariness as best he could to watch. Professor Binns, glancing up in the middle of a deadly dull lecture on the International Warlock Convention of 1289, looked amazed.

"Miss... err...?"

"Granger, Professor. I was wondering if you could tell us anything about the Chamber of Secrets," said Hermione in a clear voice.

Dean Thomas, who had been sitting with his mouth hanging open, gazing out of the window, jerked out of his trance; Lavender Brown's head came up off her arms and Neville's elbow slipped off his desk.

Professor Binns blinked.

"My subject is History of Magic," he said in his dry, wheezy voice. "I deal with facts, Miss Granger, not myths and legends." He cleared his throat with a small noise like chalk snapping and continued, "In September of that year, a subcommittee of Sardinian sorcerers –"

He stuttered to a halt. Hermione's hand was waving in the air again.

"Miss Grant?"

"Please, sir, don't legends always have a basis in fact?"

Professor Binns was looking at her in such amazement, that Harry was sure no student had ever interrupted him before, alive or dead.

"Well," said Professor Binns slowly, "yes, one could argue that, I suppose." He peered at Hermione as though he had never seen a student properly before. "However, the legend of which you speak is such a very sensational, even ludicrous tale –"

But the whole class was now hanging on Professor Binns' every word. He looked dimly at them all, every face turned to his. Without a doubt, this was the most attention he'd ever received from his students.

"Oh, very well," he said slowly. "Let me see... the Chamber of Secrets...

"You all know, of course, that Hogwarts was founded over a thousand years ago – the precise date is uncertain – by the four greatest witches and wizards of the age. The four school Houses are named after them: Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin. They built this castle together, far from prying Muggle eyes, for it was an age when magic was feared by common people, and witches and wizards suffered much persecution."

He paused, gazed blearily around the room, and continued.

"For a few years, the founders worked in harmony together, seeking out youngsters who showed signs of magic and bringing them to the castle to be educated. But then disagreements sprang up between them. A rift began to grow between Slytherin and the others. Slytherin wished to be more selective about the students admitted to Hogwarts. He believed that magical learning should be kept within all-magic families. He disliked taking students of Muggle parentage, believing them to be untrustworthy. After a while, there was a serious argument on the subject between Slytherin and Gryffindor, and Slytherin left the school."

Professor Binns paused again, pursing his lips such that he looked remarkably like a wrinkled old tortoise.

"Reliable historical sources tell us this much," he said. "But these honest facts have been obscured by the fanciful legend of the Chamber of Secrets. The story goes that Slytherin had built a hidden chamber in the castle, of which the other founders knew nothing.

"Slytherin, according to the legend, sealed the Chamber of Secrets so that none would be able to open it until his own true heir arrived at the school. The heir alone would be able to unseal the Chamber of Secrets, unleash the horror within, and use it to purge the school of all who were unworthy to study magic."

There was silence as he finished telling the story, but it wasn't the usual, sleepy silence that filled Professor Binns' classes. There was unease in the air as everyone continued to watch him, hoping for more. Professor Binns looked faintly annoyed.

"The whole thing is arrant nonsense, of course," he said. "Naturally, the school has been searched for evidence of such a chamber, many times, by the most learned witches and wizards. It does not exist. A tale told to frighten the gullible."

Hermione's hand was back in the air. "Sir – what exactly do you mean by the 'horror within' the Chamber?"

"That is believed to be some sort of monster, which the Heir of Slytherin alone can control," said Professor Binns in his dry, reedy voice.

The class exchanged nervous looks.

"I tell you, the thing does not exist," said Professor Binns, shuffling his notes. "There is no Chamber and no monster."

"But, sir," said Seamus Finnigan, "if the Chamber can only be opened by Slytherin's true heir, no one else would be able to find it, would they?"

"Nonsense, O'Flaherty," said Professor Binns in an aggravated tone. "If a long succession of Hogwarts headmasters and headmistresses haven't found the thing –"

"He makes a good point, professor," said Ginny. "Blood wards are powerful things, are they not?"

"Of course, Weasley," said Professor Binns, causing further ripples for apparently recognising Ginny. "But the wards would be centuries old, and the most powerful and learned wizards since have found no trace..."

"Salazar Slytherin was renowned for his cunning as well as his power," said Ginny. Harry frowned. "Surely, as a learned man, you would not be so quick to dismiss the idea?"

"There is no purpose to worrying about such things," said Professor Binns with an air of finality.

"Not for you, of course," said Ginny. And Harry could not decide whether that was said with trepidation or anticipation.

Binns did not hear, however, already returning to full lecture mode. For the rest of the class, that was irrelevant. They had their answer.

"I always knew Salazar Slytherin was a twisted old loony," Ron told Harry, Neville and Hermione as they fought their way through the teeming corridors at the end of the lesson to drop off their bags before dinner. Ginny had gone to meet Luna first. "A monster to 'purge' the school? I wouldn't be in his House if you paid me. Honestly, if the Sorting Hat had tried to put me in Slytherin, I'd've got the train straight back home..."

Hermione nodded fervently, but Harry didn't say anything. His stomach had just dropped unpleasantly. Harry had never mentioned how the Sorting Hat had seriously considered putting him in Slytherin. He could remember, as though it were yesterday, the small voice that had spoken in his ear when he'd placed the hat on his head a year before:

You could be great, you know, it's all here in your head, and Slytherin would help you on the way to greatness, no doubt about that...

"... thought I understood, you know?" Harry heard Neville saying as he returned to the present. "That he wanted to get rid of the Muggle-born because he was worried. We get told about witch hunts and people being burned at the stake when we're little - horror stories to make us behave ourselves."

Hermione looked a little pained. "Yeah..."

"This, though?" said Neville. "I bet he left so the others wouldn't kill him. He must have gone mad in his old age."

"Watch it!" Ron grunted as he was knocked aside for the millionth time on their way to the seventh floor.

Bouncing along behind the rowdy group of sixth years (who entirely ignored Ron) was Colin Creevey.

"Hiya, Harry!"

"Hullo, Colin," said Harry automatically.

"Harry – Harry – a boy in my class has been saying you're –" But Colin was so small he couldn't fight against the tide of people bearing him toward the Great Hall; they heard him squeak, "See you, Harry!" and he was gone.

"What's a boy in his class saying about you?" Hermione wondered.

"That I'm Slytherin's heir, I expect," said Harry, his stomach dropping another inch or so as he suddenly remembered the way Justin Finch-Fletchley had run away from him at lunchtime.

"Don't worry about it," said Neville. "They'll believe whatever they want."

The crowd thinned and they were able to climb the next staircase without difficulty.

"D'you really think there's a Chamber of Secrets?" Ron asked Hermione.

"I don't know," she said, frowning. "Dumbledore couldn't cure Mrs. Norris, and that makes me think that whatever attacked her might not be... well – human."

As she spoke, they turned a corner and found themselves at the end of the very corridor where the attack had happened. They stopped and looked. The scene was just as it had been that night, except that there was no stiff cat hanging from the torch bracket, and an empty chair stood against the wall bearing the message "The Chamber of Secrets Has Been Opened."

"That's where Filch has been keeping guard," Ron muttered.

They looked at each other. The corridor was deserted.

"Can't hurt to have a poke around," said Harry, dropping his bag and getting to his hands and knees so that he could crawl along, searching for clues.

"What sorts of monsters just Petrify their victims?" said Neville. "Seems too clean."

"Binns said the heir controls it, didn't he?" said Ron.

"Possession?" Hermione asked.

"Possibly," Neville muttered.

"Bloody hell..." said Ron. "Nothing good ever happens when someone's getting possessed."

"This will work out," said Neville firmly. "Nobody will be purged on Professor Dumbledore's watch."

"Scorch marks!" said Harry. "Here... and here."

The dark streaks on the wall and floor were more than just charred stone. Something hot had blasted a bit of the material away.

"Come and look at this!" said Hermione. "This is funny. . . ."

Harry stood up and crossed to the window next to the message on the wall. Hermione was pointing at the topmost pane, where around twenty spiders were scuttling, apparently fighting to get through a small crack. A long, silvery thread was dangling like a rope, as though they had all climbed it in their hurry to get outside.

"Have you ever seen spiders act like that?" said Hermione wonderingly.

Neville shook his head, staring in bewilderment.

"No," said Harry, "have you, Ron? Ron?"

He looked over his shoulder. Ron was standing well back and seemed to be fighting the impulse to run.

"Oh come on, Ron," said Harry. "They're moving away from you. You're fine."

"Sure," Ron said, taking a step back and looking frantically around before returning his eyes to the spiders on the wall.

Neville seemed to take pity, nudging Ron and putting himself between the redhead and a sniggering Hermione. "Remember all that water on the floor? Where did that come from? Someone's mopped it up."

"It was about here," said Ron, recovering himself to walk a few paces past Filch's chair and pointing. "Level with this door."

He reached for the brass doorknob but suddenly withdrew his hand as though he'd been burned.

"What's the matter?" said Harry.

"Can't go in there," said Ron gruffly. "That's a girls' toilet."

"Oh, Ron, there won't be anyone in there," said Hermione, standing up and coming over. "That's Moaning Myrtle's place. Come on, let's have a look."

And ignoring the large out of order sign, she opened the door. It was the gloomiest, most depressing bathroom Harry had ever set foot in. Under a large, cracked, and spotted mirror were a row of chipped sinks. The floor was damp and reflected the dull light given off by the stubs of a few candles, burning low in their holders; the wooden doors to the stalls were flaking and scratched and one of them was dangling off its hinges.

Hermione put her fingers to her lips and set off toward the end stall. When she reached it she said, "Hello, Myrtle, how are you?"

The boys went to look. Moaning Myrtle was floating above the tank of the toilet, picking at a spot on her chin.

"This is a girls' bathroom," she said, eyeing Ron, Neville and Harry suspiciously. "They're not girls."

"No," Hermione agreed. "I just wanted to show them how – er – nice it is in here."

She waved vaguely at the dirty old mirror and the damp floor.

"Say, err, Myrtle right?" said Harry. The ghost smiled shyly. "There was an attack outside here a few days ago, on Halloween. You didn't see or hear anything, did you?"

"No, I didn't," said Myrtle wistfully. "After Peeves left Sir Nicholas's party, nobody was there to tease me. So, I stayed to watch the Headless Hunt and came back quite late. The portraits were quite frantic, though. Apparently a cat died."

Myrtle seemed a bit too enthusiastic about Mrs Norris for Harry's liking, but he thanked her and bade her farewell. He was just leaving when a thought struck him.

"Sorry, Myrtle," said Harry, "the night of the attack, there was a lot of water on the ground outside?"

Myrtle's cheeks darkened slightly, and she averted her eyes. "I... I like to spend time in the u-bend. It... splashes. A lot. It's not weird!"

"Thanks again, Myrtle," said Harry. "I appreciate it."

"Anytime," she said, fiddling absently with the end of her tie.

As soon as they were out of earshot, Hermione gave a heavy sigh. "Spend time in the u-bend... Honestly, you're the first person I've seen her hold a civil conversation with, Harry. She spends time in the u-bend because she takes people breathing wrong as an insult, throws a tantrum and then dive bombs the nearest toilet."

Ron snickered quietly.

"Why in Merlin's name is she haunting a toilet?" said Neville.

Hermione shrugged. "Maybe Harry could ask her. I don't know and I don't care."

"Hermione, why were they in a girls' bathroom?" said Percy.

They stopped short, not having seen him approach.

"Err..." Hermione said, her brain rewiring itself. "We were looking for clues."

"Don't you think the detective work is better left to the staff?" said Percy. "You know, people with the resources available to them to make a proper investigation?"

"I..." said Hermione, obviously unwilling to criticise the professors even indirectly.

"We're not getting in the way," said Ron.

"Yeah," said Neville. "Maybe we'll find something they missed and we can tell them."

Percy looked around at them critically. "I should really take points for finding you coming out of there. But with current circumstances... Fine. But don't let me catch you breaking any more school rules to play sleuth."

"What's a sleuth?" said Ron.

"Where is Ginny, by the way?" said Percy. "Nine times out of ten I could count on her to be with you lot last year."

"She is behaving quite strangely," said Hermione. "Has been for a while. Only, she won't talk to me about it at all."

Percy sighed. "Perhaps I should mention it to mother. She can talk to her over the holiday or something. Anyway, good evening."

And with that, he turned away and left them standing there.

"Huh," said Neville. "I really thought he'd take points."

The Ginny they ate with that night was definitely better settled. She wasn't quite so pale as she had been, and seemed more at ease.

'Perhaps Luna calmed her down, somehow,' Harry mused.

Whatever the reasons, she was far more pleasant company. They were all sat or knelt around a table in the common room, doing various essays. Harry was just putting the finishing touches to his Charms homework when he realised that it had been at least a month since he and Ginny had so much as held hands, let alone kissed. He missed her. It was like an ache inside of him; they'd lost their closeness, not from a breakup or argument - they'd simply drifted apart.

Harry frowned, staring now across the table at his girlfriend. The more he thought about it, the more he realised that there was simply no sense to it. They had too much in common, enjoyed each other's company too much...

Ron slammed his copy of The Standard Book of Spells, Grade 2 shut with a sigh of relief. Hermione followed suit, and Harry was so surprised that she would stop working before she filled three rolls of parchment that he lost track of his prior thought process entirely.

"Who can it be, though?" she said in a quiet voice, as though continuing a conversation they had just been having. "Who'd want to frighten all the Squibs and Muggle-borns out of Hogwarts?"

"Let's think," said Ron in mock puzzlement. "Who do we know who thinks Muggle-borns are scum?"

He looked at Hermione. Hermione looked back, unconvinced. "If you're talking about Malfoy –"

"Of course I am!" said Ron. "You heard him – 'You'll be next, Mudbloods!' – come on, you've only got to look at his foul rat face to know it's him..."

Neville snorted with laughter. Even Ginny broke into a little grin. Harry saw precious few of those lately...

"Malfoy, the Heir of Slytherin?" said Hermione skeptically.

"Look at his family," said Harry, closing his books, too. "The whole lot of them have been in Slytherin; he's always boasting about it. They could easily be Slytherin's descendants. His father's definitely evil enough."

"Doubt it," Neville frowned. "I'm pretty sure there was a family who were held as the last claimants to the Slytherin seat and titles, but they died out. I'm sure of it."

"Why didn't we look into this?" said Hermione.

"Because it's hopeless," said Ginny. "The family was the Gaunts, and they did die out. So we're back to square one."

"Maybe someone inherited quietly," said Neville.

"Then we're pretty unlikely to find out about it," Ginny said derisively.

"Alright, alright," said Neville.

"Come on, we've got Hermione," said Ron. "She can find out about anything."

Hermione blushed slightly. "Thanks, but Ginny might be right. Figuring out who opened the Chamber will be difficult enough if they're a student. They might have sneaked in and started hiding out in the Chamber or something."

"So what, we do nothing?" said Harry, abhorred.

"There's nothing we can do that the professors can't," Hermione pointed out.

"That was true last year," said Harry.

Hermione sighed. "And you almost died. You-Know-Who would still be staring at that mirror if we hadn't gone down that trapdoor."

Harry gritted his teeth, ready to bite back. But as he looked into Hermione's eyes, he saw no rancour or spite. He saw only pain. "Hermione, I'm..."

Turning very pink, Hermione averted her eyes, looking vaguely at the carpet. Ron and Neville were watching proceedings with some concern.

"... sorry," Harry finished lamely. "What do you think we should do then?"

"Figure out what the monster is," said Neville with absolute certainty.

Hermione nodded. "We've got a very specific ability. Beasts that Petrify their prey can't be all that common."

"And it might be quite long lived," said Neville. "Some sort of stasis prison is possible, I suppose, but it might help us narrow down the possibilities."

"What are the chances he went for a dirty great snake?" said Ron.

"The basilisk..." said Neville. "King of the serpents. Fitting, I guess, but I thought they killed everything they looked at or something."

"I'll write it down," said Hermione. "Seems a bit obvious that he'd use a snake though."

"Library tomorrow then," said Harry.

Ron stood up. "Tonight, bed!"