Following Colin's revival, Hermione suggested that the AA could secretly brew the Polyjuice Potion so that some of them could turn into Crabbe and Goryle (and other Slytherins that Malfoy was likely to talk to), but the Slytherins in the group had given her incredulous looks. "Hello? Four of us are Slytherins, or did you forget, Hermione?" Daphne said.

"I haven't, but Malfoy's not going to be say anything revealing to any of you," Hermione responded.

"That doesn't matter," Harry said. "Or did you forget about my invisibility cloak too? All one of us needs to do is hide under it while Malfoy's in the common room and eavesdrop on whatever he's saying."

Apparently Hermione had forgotten about the cloak, for she turned scarlet and admitted that eavesdropping that way hadn't occurred to her. "It's nice to know that even brilliant people like you can forget things," Ron said teasingly and then the four Slytherins came up with a rotation on eavesdropping on Malfoy for the next couple of days.

However, all they found out when Malfoy was complaining to Crabbe and Goyle and a few other like-minded Slytherins was that while he was certainly disappointed that Sirius had shown up with cures to revive Colin and Mrs. Norris, he wasn't behind the attacks or had any idea who was. Malfoy did express the wish that he could help whomever was behind them and, as he put it, "that one of the Mudbloods in that stupid Association would die like what happened the last time the Chamber of Secrets was opened."

It had taken all of Daphne's self-control to keep from hexing Malfoy on the spot when she heard that, but before she left to report to the rest of the AA, still hidden underneath the cloak, she managed to shove his chair hard enough that he tumbled forward, the chair falling on top of him. As the other Slytherins in the common room were distracted with helping Malfoy up or seeing what happened, Daphne slipped out, muttering angrily under her breath.

In the second week of December, Professor McGonagall came around as usual, collecting names of those who would be staying at school for Christmas. For whatever reason, Malfoy had elected to stay, with Crabbe and Goyle following his lead. The AA found this very suspicious, but as they had determined that he wasn't behind the attacks, they had no idea why he was staying. Justin suggested that they stay behind in order to find out what Malfoy was up to, but Padma pointed out that it would just make him suspicious, not to mention that they'd be forced to come up with plausible reasons to explain why they were staying at Hogwarts over the holidays to their parents/guardians.

A week later, there was a piece of parchment pinned up on the notice board in the entrance hall, announcing that a Dueling Club was being started, with the first meeting that night. Since it sounded interesting and useful, the AA elected to attend, with the Ravenclaws wondering if Professor Flitwick would be the one running it, as he'd been a dueling champion in his younger days.

Unfortunately, when the AA showed up at the Great Hall for the first meeting (which had been cleared of the dining tables and had a golden stage along one wall), they saw Gilderoy Lockhart, resplendent in robes of deep plum, walk onto the stage, accompanied by none other than Professor Snape, wearing his usual black. The entire AA groaned at this, though many of them also secretly hoped that Snape would give Lockhart his due.

After Lockhart announced that he was running the Dueling Club, with Snape as his assistant, the two did their demonstration. Snape cast first, shooting out a Disarming Charm so strong that not only did Lockhart lose his grip on his wand, but he was blasted off his feet, flying backward off the stage, smashing into the wall, and sliding down it to sprawl on the floor. Several people cheered, all of them Slytherins or members of the AA.

Lockhart got unsteadily to his feet. His hat had fallen off and his wavy hair was standing on end. "Well, here you have it!" he said, tottering back onto the platform. "That was a Disarming Charm - as you see, I've lost my wand - ah, thank you, Miss Brown - yes, an excellent idea to show them that, Professor Snape, but if you don't mind my saying so, it was very obvious what you were about to do. If I had wanted to stop you it would have been only too easy - however, I felt it would be instructive to let them see..."

Several of the AA snorted derisively; Snape was looking murderous. Possibly Lockhart had noticed, because he said, "Enough demonstrating! I'm going to come amongst you now and put you all into pairs. Professor Snape, if you'd like to help me -"

They moved through the crowd, matching up partners. Unfortunately, Lockhart was the one to pair Harry with Malfoy. Harry didn't like it at all, but thought that at least it was better than Theo being paired with him instead.

Once everyone was paired up, Lockhart returned to the platform, and called. "Face your partners! And bow!"

Harry and Malfoy barely inclined their heads, not taking their eyes off each other.

"Wands at the ready!" shouted Lockhart. "When I count to three, cast your charms to Disarm your opponents - only to disarm them - we don't want any accidents - one...two... three-"

Harry swung his wand high, but Malfoy had already started on "two". His spell hit Harry so hard he felt as though he'd been hit over the head with a saucepan. He stumbled, but everything still seemed to be working, and wasting no more time, Harry pointed his wand straight at Malfoy and said the first spell that came to mind, which was, "Rictusempra!"

A jet of silver light hit Malfoy in the stomach and he doubled up, wheezing. "I said Disarm only!" Lockhart shouted in alarm over the heads of the battling crowd, as Malfoy sank to his knees; Harry had hit him with a Tickling Charm, and he could barely move for laughing. Hearing Lockhart's shout, Harry felt slightly guilty about not following orders, enough that he then cast the Disarming Charm (he didn't want Malfoy to recover enough from laughing to retaliate). As his spell was nowhere as strong as Snape's, there was only a jet of scarlet light rather than a dazzling flash and Malfoy had his wand fly out of his hand without him falling backward.

Snape, giving Harry a stern look, cast "Finite Incantatem" on Malfoy, ending his laughing fit, and helped Lockhart restore order. It looked as if nobody (other than Harry at the end) had cast the Disarming spell at all. In fact, Millicent Bulstrode seemed to have abandoned use of her wand and had poor Lavender, who was whimpering in pain, in a headlock. Dean and Ron leapt forward and pulled Millicent off, which required both their efforts as, while she slightly shorter than them, she was a lot burlier, being built along the lines of Crabbe and Goyle.

"Dear, dear," said Lockhart, skittering through the crowd, looking at the aftermath of the duels. "Up you go, Macmillan...Careful there, Miss Fawcett...Pinch it hard, it'll stop bleeding in a second, Boot -"

"I think I'd better teach you how to block unfriendly spells," said Lockhart, standing flustered in the midst of the hall. He glanced at Snape, whose black eyes glinted, and looked quickly away. "Let's have a volunteer pair." His eyes rested on Harry (who silently groaned, as he often got called up to help Lockhart with reenactments of his books during class) and called up Harry and Malfoy.

"Now, Harry," said Lockhart. "When Draco points his wand at you, you do this." He raised his wand, attempted a complicated sort of wiggling action, and dropped it. Snape smirked as Lockhart quickly picked it up, saying, "Whoops - my wand is a little overexcited -"

Snape moved closer to Malfoy, bent down, and whispered something in his ear. Malfoy smirked, too. Harry rolled his eyes and decided to do the Shield Charm, which the AA had been practicing. It should be enough to block whatever Malfoy cast, since he likely wouldn't know any spells powerful enough to get past the Shield Charm, and would be better than following Lockhart's follow-up advice of doing what he did.

"Three - two - one - go!" Lockhart shouted.

Harry quickly raised his wand and shouted, "Protego!", with a mostly invisible magical barrier appearing instantaneously. At the exact same time, Malfoy raised his wand and bellowed, "Serpensortia!" The end of his wand exploded. Harry watched, aghast, as a long black snake shot out of it, fell heavily onto the floor between them, and raised itself, ready to strike. There were screams as the crowd backed swiftly away, clearing the floor, and Harry wondered if his Shield Charm would be enough to block the snake.

"Don't move, Potter," said Snape, who had looked shocked for a brief second before swiftly assuming an impassive look. "I'll get rid of it..."

"Allow me!" shouted Lockhart. He brandished his wand at the snake and there was a loud bang; the snake, instead of vanishing, flew ten feet into the air and fell back to the floor with a loud smack. Enraged, hissing furiously, it slithered straight toward Justin and raised itself again, fangs exposed, poised to strike. Screams sounded again and Hannah tried to pull Justin away.

Harry was sure what made him do it. He wasn't even aware of deciding to it. All he knew was that he dropped the magical shield and ran forward towards the snake, shouting stupidly, "Leave him alone!" And miraculously - inexplicably - the snake slumped to the floor, docile as a thick, black garden hose, its eyes now on Harry. He felt the fear drain out of him. He knew the snake wouldn't attack anyone now, though how he knew it, he couldn't have explained.

He looked up at Justin to ask if he was all right, expecting his friend to looked relieved or grateful - but certainly not shocked and scared. "Justin, are you all right?" Harry asked, getting worried. The danger was over now, so there was no reason for his friend to still look scared. "The snake's not going to hurt you, I told it to leave you alone."

The scared look disappeared, but Justin still looked shocked. His mouth opened and closed a few times, but no sound came out. Snape stepped forward, waved his wand, and snake vanished in a small puff of black smoke,. He, too, was looking at Harry in an unpected way: it was a shrewd and calculating look, and Harry didn;t like it. He was also dimly aware of an ominous muttering all around the walls. Then he felt a tugging on the back of his robes.

"Come on," said Theo's voice in his ear. "Move - come on -"

Theo steered him out of the hall, the rest of the AA hurrying alongside or behind them (Neville and Susan had to drag Justin along, as he was still in shock). As they went through the doors, the people on either side drew away as though they were frightened of catching something. Harry didn't have a clue what was going on, and none of his friends explained anything until they were inside the Room of Requirement. Then Theo pushed Harry into an armchair and said bluntly, "You're a Parselmouth, Harry."

"I'm a what?" asked Harry blankly, before he remembered that it meant someone who could talk to snakes.

"A Parselmouth," snapped Padma. "You know, someone who can talk to snakes. Or did you forget all the research on Salazar Slytherin that we did?"

Harry shook his head and then paled as the full import sank into him. "Oh no," he said faintly. "But I can't be one! I've never spoken to snakes before, or had any speak to me! I saw a couple of snakes at the zoo before once, but one was sleeping and the other was being fed by its keeper. Neither showed any interest in me."

"Well, you certainly were speaking to the snake that Malfoy conjured," Ron said firmly. "I don't know what you said, since it was in Parseltongue and therefore sounded like hissing. It was really creepy, you know, and I'm not surprised Justin panicked."

Harry gaped at him. "I spoke a different language? But - I didn't realize - how can I speak a language without knowing I can speak it?"

"We don't know," said Susan. "The point is that you were speaking Parseltongue, and gave Justin a fright."

"I'm s-sorry," Justin said weakly, getting over his shock enough to finally speak. "I know y-you were keeping the snake f-from attacking me, Harry, b-but it was s-still -"

"It's all right, Justin," Harry said. "I can imagine how scary it was for you."

"And now the whole school's going to think you're Slytherin's great-great-great-great-great-grandson or something, Harry," said Ron.

"But I'm not!" protested Harry, with a panic he couldn't quite explain. "And now everyone's going to start hating Slytherin again, because I'm in it!"

"Not everyone," snapped Parvati. "Or do you think the rest of the AA would turn on you, Theo, Daphne, and Tracey? And I'm pretty sure the prefects will see reason like they did last time people were distrusting Slytherin."

"And don't worry, we know for a fact that you aren't descended from Salazar Slytherin," Hermione said. "Maybe related to him or one of his descendants via marriage, since pretty much all the wizarding families in Britain have intermarried, but no more than that."

That much was certainly true, for the journals and a book detailing the family tree in the Potter family vault showed that the Harry's branch of the Potter family tree had no links to Slytherin or his descendants, and Eric's research had shown that the Evans family could trace their descent to a squib from the Fawcett family, who didn't have the links either. In fact, the Potter family could claim better relation to Godric Gryffindor's line (though they weren't direct descendants).

"Yeah, but the rest of the school isn't going to know that," Harry muttered. "Ugh, I suppose I had better let Aunt Lia and Uncle Sirius know what's going on." He pulled out his two-way mirror and called them.

Sirius answered and frowned when his godson explained what happened in the last half of the Dueling Club meeting and about being a Parselmouth. "That's certainly odd. None of the Potters were known to have that ability, and your parents certainly didn't. Being a Parselmouth tends to run in families, like how the Black family is known to sometimes produce a Metamorphmagus. Maybe when Riddle tried to kill you as a baby, he somehow transferred the ability to you, Harry. I'll discuss this with Lia, Remus, and Dumbledore. But if you are a Parselmouth, that may explain the voice you were hearing those two times, but your friends wouldn't. It would be a hissing noise to them, and that's assuming they could hear it over their conversation."

"Then that means, coupled with what Colin said he saw, that Slytherin's monster has to be some sort of snake!" exclaimed Harry.

"That makes sense," said Anthony thoughtfully. "Maybe it is a basilisk. I know its gaze kills, but since Mrs. Norris must have seen its reflection in a puddle and Colin saw it through his camera, it resulted in Petrification instead."

"That is what Lia and I have been thinking," said Sirius. "Eric and I are going to Hogwarts to discuss this with Dumbledore tomorrow. Lia has work, or she'd come too. We'll work out where the Chamber of Secrets must be and get the basilisk taken care of. A few roosters should do the trick."

The AA was relieved to hear that and the call ended.

By next morning, however, the snow that had begun in the night had turned into a blizzard so thick that the last Herbology lessons of the term were canceled; Professor Sprout wanted to fit socks and scarves on the Mandrakes, a tricky operation she would entrust no one else. At morning break, the Hufflepuff members of the AA reported that they'd been in the library during the canceled class-time and had to talk Ernie Macmillian and Zacharias Smith out of their belief that Harry was the Heir of Slytherin. Ernie had eventually acknowledged that Harry hadn't been anywhere near the scene of the two attacks and accepted Justin's insistence that his friend had kept the snake from attacking, but Zacharias had stubbornly clung to his belief that Harry, or at least one of the Slytherins, was involved.

"Just ignore Smith," said Harry. "He doesn't really like the AA to begin with, and wasn't he one of the first people to think the Slytherins were involved after Mrs. Norris's Petrification? As long as most of the other Hufflepuffs don't think like him I'm fine."

"Well, Cedric knows you're not the Heir or behind the attacks, our prefects think the same, and they're doing damage control to keep the other Hufflepuffs from being idiots and following Smith's lead," said Susan.

The bell rang, signalling that break was over, and they scattered for their respective classes. It was after class, when the students were heading to the Great Hall for lunch, when it happened. Justin, Theodore, and Anthony left for the bathroom. On their way back, the three were walking near Moaning Myrtle's bathroom when they heard Luna exclaim, "Ginny! Wait up! What's the matter with you?"

The trio turned just in time to see Ginny walk into the bathroom, with Luna running behind her. Even though it was a girls' bathroom, the three boys peeked in to see what was going on. Ginny, holding on to what was presumably the Gryffinclaw diary, was standing in front of a sink and hissing at it. A concerned looking Luna was tugging on her arm, but Ginny appeared to take no notice as to what was happening. Suddenly, the tap glowed with a brilliant white light and began to spin. Next second, the sink began to move; the sink, in fact, sank, right out of sight, leaving a large pipe exposed, a pipe wide enough for a man to slide into.

Anthony dashed forward and pulled Ginny back. Theo tugged the diary out of her hands and flipped through it. It was completely blank, which made him wonder if the Gryffinclaws had vanished all the writing they'd done in it, until he saw that inside the front cover was written "T. M. Riddle." Cursing the fact that the AA hadn't thought to ask to examine the diary the Gryffinclaws were writing in, he pocketed it and snapped, "Let's get out of here before the basilisk shows up and we either die or get Petrified."

The five made a hasty retreat, with Anthony and Justin holding on tightly to Ginny, who was starting to struggle, by her arms. Partway to Professor Dumbledore's office, she stopped struggling and appeared to come to herself. "What's going on?" she demanded. "Anthony, Justin, why are you holding me?"

"You were possessed," Theo said. "Why didn't your quartet show us the diary you guys were writing in? The T. M. Riddle that once owned it? That's the birth name of You-Know-Who. If we'd taken a good look at the diary, we could have told you that, and had you turn it in to Dumbledore at once."

Luna's eyes got bigger than usual, while Ginny turned pale, her freckles more noticeable. "You mean Tom tricked us?"

"Yes," said Anthony. "From what we saw, you were being possessed by Riddle's spirit or whatever that's in the diary into opening the Chamber of Secrets. I'm guessing those two times when Colin and Matt didn't remember what they were doing was when they were possessed."

Ginny looked as if she were about to cry and mumbled something about being expelled.

"You're not getting expelled," Justin said patiently. "Nor is Colin and Liam. The diary was possessing you, so it can all be blamed on Tom Riddle."

By this point, they had reached the gargoyle in front of the entrance to the headmaster's office, and that was when they realized that none of them knew the password. Theo was about to rush off to the Great Hall to get one of the teachers to help them when the gargoyle suddenly moved and Professor Dumbledore stepped out, Sirius and Remus behind him.

"Oh hello," said Professor Dumbledore. "I'm sorry, but my guests and I have a matter to handle, so you five will have to wait until we're done to meet with me."

"Actually, it has to do with the Chamber of Secrets," Justin said. "We've worked out what's going on."

Theodore pulled out Riddle's diary from his pocket and handed it over to Sirius. "The Gryffinclaw quartet have been writing in a diary. I finally got a good look at it. It was blank, so at first I assumed that they were vanishing what they wrote, but then I saw that the name written in the cover was 'T. M. Riddle'."

Anthony followed up with an explanation of finding Ginny hissing at a sink inside Moaning Myrtle's bathroom and making it move aside, revealing a pipe/slide that was presumably the entrance to the Chamber of Secrets, and their theory that the diary of Tom Riddle had been possessing her, Colin, and Matt. Luna added that after what had happened when Matt and Colin both had gone to the bathroom alone, she had run after Ginny.

"Oh, and I think I didn't escape being possessed either," Luna said thoughtfully. "After dinner, I apparently wandered off until the Dueling Club meeting. I have no memory of it, but before I left with my friends for the meeting, I suddenly found that my coat and robes had chicken feathers on them."

Sirius and Remus exchanged looks and Professor Dumbledore said, "Hagrid came into my office earlier to report that he had found a second rooster dead and wanted my permission to cast a protective charm on the chicken coop. I assume you must have been possessed briefly into killing the school roosters, Miss Lovegood, which provides further proof that there is a basilisk in the school. Sirius, Remus, and I were going to question Miss Warren, that is Myrtle. Now that we know the location of the Chamber of Secrets, or at least the entrance to it, things will be easier."

"Could one of you get Harry?" Sirius asked. "In the time since you guys left the bathroom, the sink could have moved back to it's original space, so we'll need Harry to open the entrance again. We adults will go down with some Transfigured roosters and get them to crow in order to kill the basilisk. Once it's all been taken care of, Professor Dumbledore has given permission for the AA to go down for a look to satisfy your curiosity, since you guys helped us with this."

"In addition, all the members of the AA will get twenty-five points each for your help," said Professor Dumbledore. "And Mr. Finch-Fletchley, Mr. Nott, and Mr. Goldstein, you each get an additional thirty points for discovering that Riddle's diary was possessing the Gryffinclaw quartet, was it, and bringing it to my attention. Miss Weasley and Miss Lovegood, you can explain to Mr. Creevy and Mr. Stanley what was going on, in private, and rest assured that none of you will be punished for this. Greater witches and wizards than you four have been hoodwinked by Tom Riddle."

"Thank you, Professor Dumbledore," Ginny and Luna said.

"Since what happened is supposed to be kept quiet," Remus said, "I'll ask Ellie to come and check up on the Gryffinclaw quartet to make sure that none of you are suffering adversely from being possessed, okay?"

Ginny and Luna nodded and the two girls left. Anthony left to get, not just Harry, but the rest of the AA, since they were allowed to know what was going on and check out the Chamber of Secrets once the basilisk was killed. Once the whole group was gathered, they crowded inside the bathroom. As Sirius had surmised, the sink had moved back in place. Professor Dumbledore questioned Myrtle about her death, and then Harry stepped in front of the sink concealing the entrance. According the Myrtle, the tap had never worked, and etched on the side was a copper snake. It took a couple of tries, with Harry having to pretend that the etched snake was real, before he succeeded in saying, "Open up," in Parseltongue.

Once the sink slid aside, revealing the slide, Sirius, Remus, and Dumbledore Transfigured the rocks they had in their pockets into roosters and stuck them in conjured cages, with cloths covering the cages. Once down in the Chamber, they planned to whisk off the cloths and conjure up a great burst of light, enough to set the roosters crowing. If that didn't work, then they would do the Imperius Curse to force the crowing, which since the roosters were Transfigured, wouldn't get them in trouble for casting an Unforgiveable Curse. All three men also blindfolded themselves, to avoid the risk of accidentally gazing into the basilisk's eyes and dying.

After perhaps forty minutes of waiting, they returned. It had taken a bit of a walk to get to the main chamber, with them passing the shed skin of the basilisk on the way. Once there, Dumbledore had conjured a large slab of meat and did another spell to intensify the smell of the meat in order to lure out the basilisk. As soon as it had appeared, the roosters were set to crowing, killing it. The AA were now allowed to take a look down in the Chamber of Secrets, with Sirius and Remus escorting them, and Professor Dumbledore was going to make arrangements to have the basilisk's body harvested for potion ingredients and the like and make sure that Salazar Slytherin hadn't left anything else behind (such as other nasty surprises or his private writings) before sealing up the chamber.

"I'll make an announcement at dinnertime about how everything had been dealt with and the danger is gone, but not all the full details," Dumbledore added. "There is no need for the Gryffinclaw quartet to face any trouble from their fellow students about being hoodwinked into opening the Chamber. And naturally, please keep your association's part in all this quiet as well, all right? I will further examine Riddle's diary, with Sirius and Remus's help, and destroy it if necessary."

Harry remembered what Sirius had told him last year about finding Slytherin's locket, turned into a Dark object, in the Black house. "Tom Riddle turned his diary into a Dark object, didn't he? Like he did with Slytherin's locket."

"I assume so," Sirius said. "Dumbledore and I will see if the diary was turned into the same type of Dark object as the locket and destroy it."

The AA looked satisfied with that and then, one by one, followed Remus and Sirius down the pipe. It was quite creepy going down the tunnel to the main chamber, but they all had lit their wands with the "Lumos" spell, so they could see clearly. They passed the shed skin, which looked to be about twenty feet long, and Harry paused to examine it for a minute and wonder what potions the skin could be useful in. The main chamber had the basilisk's corpse, which was longer than the shed skin, and a giant statue of Salazar Slytherin. Harry spoke Parseltongue on the statue to see if revealed any hidden passages or rooms.

The large hole in its mouth closed up, proving that it was where the basilisk had slithered out from. Harry spoke again, opening up the mouth, and Remus made his way up to peer through. He found signs that the basilisk had indeed come from there, but the chamber hidden behind the statue contained nothing else, so far as he could see.

"I'm sure Professor Dumbledore will do a more thorough search to make sure nothing has been missed, but there doesn't seem to be anything of interest other than the basilisk," said Remus. "And that's only useful for potion ingredients and the venom being handy for destroying -" He broke off, realizing that he almost said too much, but the AA suspected that he was going to say that basilisk venom was handy for destroying what Dark objects the locket and diary were.

Sirius took the time to pry sixteen scales from the basilisk, so that each of the AA members could have a souvenir of this, and then they headed back. As by this point lunch was over, he and Remus took the AA to the kitchens so that they could get a bite to eat, and then the AA went to their afternoon classes while Sirius and Remus left to confer further with Dumbledore.