Draco skidded into the girl's third floor bathroom to find Weasley, Longbottom, and Lockhart there.
"What are you doing here?" he blurted.
"I think we could ask you the same," Weasley said, and Draco noticed something odd. Weasley and Longbottom both had their wands out, pointed at Lockhart's back. He was about to ask what that was about, when Myrtle wailed.
"Draco!" she cried. "Did you want to hear about my death, too?"
Draco shivered a little, because he most certainly did not. But that answer would mean a very upset Myrtle, so he nodded, and tried to tune her out, walking over to the sinks instead, and looking for the right one.
" – and then there were these great, yellow eyes, over there."
"Right where Malfoy's standing?" Longbottom asked.
"Move, Malfoy," Weasley said, rudely. Draco stepped aside obligingly. Longbottom stood where he'd been, inspecting first the floor, then the pipes, then the sink itself.
"There's a little snake on this faucet!" Longbottom cried triumphantly.
"Right," said Weasley. "How do we open it, Myrtle?"
"I don't know," Myrtle whined. "All I heard was a bunch of funny noises."
"Did it, perhaps, sound like this?" Draco did his best imitation of Parseltongue.
"Yes!" Myrtle cried, at the same time as the sinks slid open, revealing the entrance to the Chamber.
"You're the Heir!" Weasley accused, and Longbottom and Lockhart both looked at him fearfully.
"I'm not the Heir, you dolts," Draco rolled his eyes.
"But you just opened the Chamber," Longbottom pointed out. "If it's not you, then who is?"
"That title belongs to Tom Riddle," Draco told them.
"Who?" Weasley asked, just as Draco had thought he would.
"Look, are we going down there or what?" Draco asked, impatiently. He didn't have time for all this nonsense.
"Yes," Weasley said, and he poked Lockhart in the back with his taped-up wand. "You first."
"I – me?" Lockhart smiled round at them. "No, no, boys, I think I should definitely be last, just in case, you know –"
Weasley pushed him forward, and Lockhart stumbled, caught himself for a moment on the edge of the sink, and then fell down the hole. He screamed all the way down.
"That was satisfying," Weasley said, staring down into the pipe. Longbottom nodded.
"For once, I agree with you," Draco said dryly, and then he jumped down the pipe.
It was positively filthy down at the bottom. Draco was trying to breathe as little as possible through his nose as they trekked through the cave-like passage. At least they knew they were going the right way, he thought, as they passed an enormous, decaying snake skin. He coughed as the smell from it hit his nostrils.
Behind him, Weasley, Longbottom, and Lockhart weren't faring much better. Weasley sounded like he was hacking up a lung.
Suddenly, Draco heard the unmistakable sounds of a scuffle, and turned to see Lockhart standing triumphantly over Weasley, the latter's wand in his grasp. Longbottom had backed away from them, closer to Draco, and his wand trembled in his hand.
"Ha!" Lockhart cried. "The adventure ends here, boys! I shall take a bit of this skin back up to the school, tell them I was too late to save the girl, and that you three tragically lost your minds at the sight of her mangled body — say good-bye to your memories!"
"Obliviate!" he shouted, and Weasley's taped-up wand exploded. Draco dropped to the ground, covering his head, and saw Longbottom copying him. Rocks tumbled down from somewhere above them, bouncing off their arms painfully.
When the shaking finally seemed to have stopped, Draco lifted his head carefully. The dust was still settling, but there was no way they could get back now. The rocks entirely blocked the passage. Weasley and Lockhart were no longer visible.
"Ron!" Longbottom shouted. There was a groan from the other side.
"I'm here! I'm okay," came the response. Longbottom gave a huge sigh of relief. "Lockhart's not though – got hit with the spell he meant for me."
There was a giggle, and then an "ow," which must have been Weasley kicking Lockhart. Well, at least they hadn't killed a professor, Draco thought, even if he was a shit one.
"What now?" Weasley asked uncertainly.
"Try and shift some of this, Weasley," Draco shouted, finally speaking up. "We'll go ahead, but we'll need a way to get back out."
There was a bit of a pause, where Draco was sure that Weasley was trying to decide if it was worth it to take orders from him.
"Alright," he said. "I'll just – yeah." There was the sound of rocks falling, as Weasley began his work, and Draco glanced at Longbottom, who, although he was white as a sheet, nodded back decisively.
Around the bend, they encountered a wall, with two stone snakes carved into it, coiling around each other. Their eyes were green gemstones that seemed to glow.
"Can you do that thing again?" Longbottom asked, not taking his eyes off the snakes.
"Yeah," Draco said, and he repeated the same thing he'd said in the girl's bathroom. The serpents uncoiled from each other, and the wall split down the middle, and slid open.
Cautiously, Draco and Longbottom walked down the long hall. Pillars carved with serpents rose from pools of water on either side, and their footsteps, occasionally splashing through puddles, were the only sound. At the end of the hall, two figures became visible, and Draco recognized them both as they got closer.
Tom turned and smiled at them, the youngest Weasley pale and unmoving at his feet, clutching the little black diary to her chest.
"Draco!" Tom cried. "How delightful. I don't believe we finished our conversation, before." His gaze grew dark, and Draco shuddered.
"Wh-what've you done t-to Ginny?" Longbottom stuttered, and Tom turned uncaring eyes on him.
"Well, that's an interesting question," said Tom pleasantly. "And quite a long story. I suppose the real reason Ginny Weasley's like this is because she opened her heart and spilled all her secrets to an invisible stranger."
"What do you mean?" Draco demanded.
"Poor little Ginny Weasley," Tom said softly, eyes flicking back to Draco. "Pouring out her soul to me – literally. It's very bothersome to listen to a whiny little girl, but I suppose the reward was worth it."
"You're draining her," Draco said.
"It won't be long now," Tom smiled. "She put too much into me. Enough to allow me to leave the pages."
Longbottom scrambled forward and knelt by the Weasley girl, shaking her shoulder, his wand clattering to the floor.
"Ginny, Ginny," he said, desperately. Nothing happened. Tom turned to Draco, who suddenly noticed that he'd somehow got hold of Longbottom's wand. He squeezed his hand around his own wand tightly, although he knew it probably wouldn't do much good.
"Now, what shall we do with you and your friend, here?" He asked, rhetorically. "It seems the Malfoys are not so loyal, after all. Perhaps they should be reminded of where their allegiance is due."
"We're not afraid of you," Longbottom said, immediately ruining the effect by standing and wiping his nose. "Heir of Slytherin, or whatever you are, anyway."
Tom laughed, clear and cold. "Oh, little boy," he said, still smiling widely. "I am Lord Voldemort."
Longbottom wavered, but didn't back down. "D-Dumbledore said that h-help will always b-be given at H-Hogwarts t-to those who ask for it," he said, although he didn't sound totally certain.
Draco wondered what kind of nonsense he was spouting now, and then a musical trill sounded, echoing in the Chamber. A crimson bird, as big as a swan, and with a great golden tail, swooped down through the hall. It was clutching something in its golden talons, which it dropped into Longbottom's arms before sweeping away again.
Longbottom unfolded the object.
It was the Sorting Hat.
Draco stared at it in disbelief, with a sort of sinking feeling in his stomach. Tom only laughed.
"This is what Dumbledore sends his defenders?" he said. "Well, let's see if it helps you against the powers of Lord Voldemort, Heir of Slytherin."
He turned to the giant statue of Slytherin that towered up at the back of the room, and spoke something in Parseltongue to it.
"What's he saying?" Longbottom asked him urgently.
"I don't know, I don't actually speak Parseltongue!" Draco whispered. "But he's probably summoning the basilisk."
"Oh," said Longbottom. "What do we do?"
Draco paused. The great stone mouth of Slytherin had slid open, and the harsh sound of scales on rock grew louder. Tom turned and smirked at them.
"Run," Draco said, dashing toward the side of the Chamber, where he could see the opening of a big pipe.
"Do you have a plan?" Longbottom whispered, as they crouched by a grating.
"A bit of one," Draco admitted. "Are you still carrying that old rag?"
"It's the sorting hat! I wasn't going to- "
They both stared at the opening of the hat. Something was slowly glimmering into existence in the opening of the hat. It was a handle – no, a hilt – Draco realized, as Longbottom tugged a sword out of the hat.
"Right," he said, eyeing the sword speculatively. "New plan. Stab it."
"And keep your eyes shut, while you're at it," Draco added.
"How am I supposed to stab it if my eyes are shut?" Longbottom asked in a panicked whisper, clamping his eyelids firmly together.
Draco didn't answer. The slithering noise was coming closer. The basilisk was almost on them. Draco watched, keeping his eyes just barely open, and as soon as he saw the nose of the giant snake, he pushed Longbottom forward.
Longbottom lurched forward wildly, swinging the sword like he'd never taken fencing lessons before in his life, which – oh.
At any rate, his random swinging managed to hit something, and the basilisk reared back, hitting its head on the top of the pipe. Longbottom was standing, frozen, and Draco ran forward, grabbing his sleeve and pulling him further down the pipe. They reemerged in the Chamber again, on the other side, Longbottom stumbling down.
"What just happened?"
"I think you defanged it," Draco told him. He'd seen several long, whitish-looking fangs scattered on the floor as they rushed past the snake, so at least they wouldn't have to worry about being bitten.
"A basilisk does not need fangs to kill you," Tom scoffed from behind them, and Draco jumped in surprise. He'd forgotten he was there, standing quietly at the foot of the Slytherin statue. Tom called out something in Parseltongue and smiled at them. "Take your time dying, boys. I'm in no hurry."
"We're going to die," Longbottom whimpered, as they heard the snake coming down the pipe again.
"Close your eyes," Draco said.
"Merlin," Longbottom swore, "We're going to die. My gran will be so upset." He closed his eyes, though, and held the sword outstretched. Draco made himself breathe out, long and slow. He had to time this perfectly.
As soon as he saw the snout of basilisk at the mouth of the pipe, he closed his own eyes, and reached into his pocket. The serpent hissed, and snapped its jaws, and Draco felt something fly past them.
He pulled the mirror free of his robes and held it up.
"NO!" he heard Tom scream. "No, what have you done!"
Draco instinctively cracked one eyelid. Not more than a meter away from his face, the basilisk was poised, ready to strike – and turned frozen, dead. Draco realized too late that he'd made the mistake of looking directly into its open eyes, but after a moment of panic, found that he was still very much alive. The basilisk's death stare must not work when it was dead.
"You," Tom snarled, his face contorting nastily. Draco started to back up, pushing Longbottom along behind him.
"Not much longer now, little Malfoy," Tom practically hissed. "You and your friend will pay for this."
Longbottom stopped, and Draco turned to see that he'd run into the Weasley girl's legs. She didn't look good; in fact, she looked almost as dead as Myrtle in the memory.
Draco's heart raced faster. What could he do? He had his wand, but he was no duelist, and this was You-Know-Who. He had a mirror, and Longbottom had a sword, and-
His gaze landed on the diary, and then on something resting on the floor at their feet.
It all came back to that, didn't it?
Draco dropped, grabbing the diary off of Weasley's chest, scooped up the lone basilisk fang from the floor, and stabbed it straight through the black leather.
Tom screamed bloody murder.
Well, more like inky murder, Draco thought. The diary was oozing black ink from between the pages, and Tom was fracturing into pieces, Longbottom's wand falling from his hands. Draco dug the fang deeper into the pages and felt it hit the stone floor of the Chamber.
Tom screamed one last time, loud and long, and then he was just… gone. Like he'd never been there at all.
The Weasley girl gasped and sat straight up.
"Neville!" She cried, and then, with confusion, "Malfoy?"
"It's alright Ginny," Longbottom said comfortingly. "You're safe now."
Weasley looked confused, her eyes only growing wider when she saw the frozen, dead form of the basilisk.
"He's gone," Draco told her, holding up the pierced-through diary.
"Oh, thank you," Weasley breathed, and she moved like she was going to hug him. Draco leaned away quickly.
"Right," he said. "I'm sure you're very grateful, but I'd rather it not be common knowledge that I was down here with you lot. So."
He passed the book over to Longbottom, who nodded slowly.
"Shall we get out of here, then?"