Just a couple of things about this chapter: firstly, there is quite a lot of Rowling's original dialogue, probably more than there will ever be again in this story. That said, I have changed elements of The Heir of Slytherin chapter; partially for pacing reasons, but also because Lena's presence would obviously affect, at least in small ways, how things play out. Hopefully the result is nothing too off-putting :)

For a brief moment, Harry just stared at Lena. Then, to her shock, anger suddenly darkened his face, and he raised his wand, opening his mouth to cast... well, something decidedly unfriendly.

Instinctively, Lena swiped her hand left-to-right, and Harry's wand flew from his grasp. But because her response had been so uncontrolled, the wand, instead of coming to her, spun through the air before clattering to the ground somewhere far to her right.

"What the hell–" Lena began to exclaim, but Harry's furious voice drowned her out.

"LIAR!" he shouted. "YOU'RE A LIAR!" Then he looked behind her, and his face paled. "Ginny!" he gasped, and ran to the unconscious girl.

Lena watched him in disbelief, speechless. Why the hell had he reacted to seeing her like that?

Harry reached Ginny and dropped to his knees. Lena could hear him whispering, "Ginny, don't be dead! Please don't be dead!" He shook her shoulders. "Please wake up," he muttered.

Slowly, Lena approached the two young Gryffindors, and hesitantly called out to Harry, "She's not dead."

Harry looked back at her, and Lena almost flinched at the hostility in his stare. "What did you do to her?" he said angrily.

Lena halted. "I haven't done anything," she said, confused. "Harry, why–"

"If you haven't done anything, then why won't she wake up?"

Still bewildered by Harry's enmity towards her, Lena tried to explain, "She's still alive at the moment, but she is dying."

"I trusted you," said Harry suddenly, his voice full of venom. "Told you things I haven't told anyone else, not even Ron or Hermione. And the whole time–"

"The whole time what?" interrupted Lena, gesturing helplessly.

"IT WAS YOU!" yelled Harry, standing back up. "The whole time it was YOU!"

Finally, it dawned on Lena. "You think I'm the heir."

Harry glared at her. "Just stop pretending," he said. "I know. Why else would you be down here?"

Lena sighed, pushing some loose hair back behind her ear. "I don't know what it is you think you know," she said, "but I'm not–"

"He's your father."

Lena went rigid. "I'm sorry?" she said at last, barely managing to stop her voice from shaking.

"It's why you acted so weird whenever we talked about him," said Harry quietly. "Voldemort's your father."

As far as Lena could remember, she had only ever lost control of her magic when she was very afraid or enraged. Or both. But hearing Harry accuse her of being Voldemort's daughter...

Perhaps it was a delayed reaction to meeting Riddle. Or maybe it was the poor state of her health. Quite possibly, it was the combined effect of the two. Whatever it was, it was the final breaking point for Lena. After years of being pulled in so many different directions – ambition, restraint, self-preservation, compassion, wanting to be better but unable to let go of the darkness that had protected her and made her who she was – Lena fell apart.

It was like an earthquake had hit the Chamber. The ground began to tremble. Cracks started to appear. Dust and chips of stone fell from the high ceiling.

Harry was looking around, his anger slowly being replaced by fear. "What – what are you doing?" he called out nervously.

Lena didn't respond; her head had started to painfully throb. Clutching it, she whimpered. Desperately, she tried to keep a hold of her Occlumency shield. But there was so much happening in her mind. Her head felt full – fuller than it had even been. The mental barrier was struggling to keep seventeen years' worth of memories, feelings and thoughts inside her head. It was like a rubber band, being pulled more and more taut.

Then it snapped.

And for the first time since she was five years old, Lena's mind was completely vulnerable. But that wasn't the worst thing. One of the memories that had been pushing at the protective barrier suddenly found itself no longer facing any resistance, and was propelled out of Lena's head – and into Harry's.

It was more of an image than a memory. The image Lena had seen in the Mirror of Erised: herself, standing next to Voldemort, who was smiling at her proudly, his hand resting on her shoulder.

Lena knew Harry had seen it when she heard his shocked gasp. Her eyes met his, and she knew he was sickened at the thought that he had regarded Lena – someone who cared for his parents' murderer – as a friend. She opened her mouth, wanting to explain, but no words came. Instead, a jolt of pain ran through her entire body, and she cried out, staggering backwards.

The shaking of the Chamber floor intensified. A loud noise drew Lena's attention to a nearby pillar. Although her vision was hazy, she saw that a large crack was running up through the column. A few seconds later, the pillar split in half and crashed to the ground, the stone shattering on impact.

Another wave of excruciating pain ran through Lena, making her whimper. She didn't understand what was causing it – it had never happened before when she'd lost control. But now, the destruction she caused wasn't just happening around her, it was also inside of her. And it hurt almost as much as the Cruciatus Curse.

She clutched her sides and screamed as pain ripped through her again. The stone pieces from the fallen pillar rose into the air and began to whirl around Lena. She could hear Harry shouting at her to stop. Lena wanted to tell him she could as much stop what she was doing as she could stop the sun from rising, but her head hurt too much to form a coherent sentence.

Then Lena caught sight of the back of her hands. The veins, so prominent under her pale skin, were turning black.

Finally, she understood. It was her own magic that was attacking her body. It was trying to stop her, to stop the destruction she was causing around her.

So Lena stopped fighting and let the pain completely take hold of her. And as she screamed, the debris flying through the air settled back on the ground, which began to gradually stop shaking. And once her scream had died out, everything was once again quiet and still.

For the second time that day, Lena felt herself falling backwards. But this time, something – or rather, someone – caught her before her head hit the ground.

"I've got you," she heard a voice murmur in her ear.

It was Riddle. Gently, he set her down on the ground. Lena tried to look back at him, but her vision had gone black. She heard Harry saying something, but couldn't make out the words. A ringing in her ears, gradually getting louder, was blocking out all external noise.

There had only been two other times in Lena's life when she had felt as weak as she did now. Both of those instances had been the result of extremely Dark magic. But this time, it had been entirely self-inflicted.

Semi-conscious, Lena half-sat, half-lay on the ground, light-headed. Once the ringing in her ears began to subside, she became aware that Riddle and Harry were talking. But she found she couldn't actually understand a word of what they were saying. She squinted at them, trying to see their facial expressions, but her vision – although no longer black – was incredibly blurry, like an out-of-focus telescope.

She rubbed her temple, but her senses remained impaired. All she wanted to do was properly lie down and sleep. But then Lena found herself staring at Ginny Weasley, lying still on the ground.

If Lena went to sleep now, she would probably wake up in a day or two, maybe three.

But Ginny might never wake up.

The thought gave Lena some much needed clarity. Pushing herself up so she was sitting, Riddle's voice finally came into focus.

"–so that one day, with luck, I would be able to lead another in my footsteps and finish Salazar Slytherin's noble work."

Her vision now clearing, Lena saw that Harry was standing near Ginny and facing Riddle, whose back was turned to Lena. Neither of them had noticed Lena's change in position.

"Well, you haven't finished it," said Harry triumphantly. "No one's died this time, not even the cat. In a few hours the Mandrake Draught will be ready and everyone who was Petrified will be all right again."

So presumably Harry now knew that Riddle was the heir. 'But does he know who Riddle became?' wondered Lena.

"Haven't I already told you," said Riddle quietly, "that killing Mudbloods doesn't matter to me anymore? For many months now, my new target has been – you."

If the confusion on Harry's face was any indication, he was still unaware that he was talking to a young Voldemort.

"Imagine how angry I was when the next time my diary was opened, it was Ginny who was writing to me, not you," continued Riddle. "She saw you with the diary, you see, and panicked. What if you found out how to work it, and I repeated all of her secrets to you? What if, even worse, I told you who'd been strangling roosters? So the foolish little brat waited until your dormitory was deserted and stole it back. But I knew what I must do. It was clear to me that you were on the trail of Slytherin's heir. From everything Ginny had told me about you, I knew you would go to any lengths to solve the mystery – particularly if one of your best friends was attacked. And Ginny had told me the whole school was buzzing because you could speak Parseltongue... so I made Ginny write her own farewell on the wall and–"

"That's when I arrived," said Lena softly, drawing Harry's gaze to her and causing Riddle to turn around.

Concern was written all over Riddle's face as he looked at her. Lena wasn't sure how she felt about that. "Yes," he said, his voice just as quiet. "Then you showed up."

"Why?" asked Harry, watching Lena warily.

"Because I finally came to the realisation that Myrtle was the victim of Slytherin's monster fifty years ago," replied Lena. "And then I was able to draw one conclusion from another to figure out that the entrance to the Chamber was in her bathroom." She glanced up at Riddle. "But I ran into Ginny before I could get there."

Riddle half-smiled at Lena before turning back around. "And as I told you before," he said to Harry, "I was... eager to meet Lena. So I had Ginny stun Lena, then levitate her and bring her down here. Unfortunately, the Stun was a little over-enthusiastic, so I had to wait quite some time for Lena to wake up. Which meant I was left with just Ginny for company for several hours." Riddle's tone became noticeably crueller. "She struggled and cried and became very boring. But there isn't much life left in her: she put too much into the diary, into me. Enough to let me leave its pages at last. I've been waiting for you to appear since we arrived here. I knew you'd come. I have many questions for you, Harry Potter."

"Like what?" Harry spat, his fists clenched.

"Well," said Riddle, "how is it that a baby with no extraordinary magical talent managed to defeat the greatest wizard of all time?" He began to pace. "How did you escape with nothing but a scar, while Lord Voldemort's powers were destroyed?" He came to a stop, standing an equal distance between Harry and Lena, facing them both. Which meant that Lena could now see that there was a red gleam in Riddle's eyes.

"Why do you care how I escaped?" said Harry slowly. "Voldemort was after your time."

"No," said Lena. "Harry, don't you understand? Voldemort is what comes next." Her eyes flicked over to Riddle, who was watching her with a smirk. "It's his future."

Harry looked between Lena and Riddle, confused. "I don't–"

"Perhaps," interrupted Riddle, pulling Harry's wand from his pocket, "I should just show you." He began to trace the wand through the air, writing three shimmering words:

TOM MARVOLO RIDDLE

Then he waved the wand once, and the letters of his name rearranged themselves:

I AM LORD VOLDEMORT

'So that's how he got the name,' noted Lena to herself. It was something she had wondered for a long time.

"You see?" whispered Riddle, his attention now entirely focused on Harry, whose face had frozen in shock and horror. "It was a name I was already using at Hogwarts, to my most intimate friends only, of course. You think I was going to use my filthy Muggle father's name forever? I, in whose veins runs the blood of Salazar Slytherin himself, through my mother's side? I, keep the name of a foul common Muggle, who abandoned me even before I was born, just because he found out his wife was a witch? No, Harry. I fashioned myself a new name, a name I knew wizards everywhere would one day fear to speak, when I had become the greatest sorcerer in the world!"

For the first time in her life, Lena truly understood what motivated Voldemort beyond power. And it wasn't just the anger he felt towards his father. It was about honouring the connection to the one person who shared his blood that hadn't failed him: Slytherin himself. It was what gave him his identity.

She was pulled from her thoughts by the sound of Harry's quiet, hatred-filled voice.

"You're not."

"Not what?" snapped Riddle.

"Not the greatest sorcerer in the world," said Harry, breathing fast. "Sorry to disappoint you, and all that, but the greatest wizard in the world is Albus Dumbledore. Everyone says so. Even when you were strong, you didn't dare try and take over Hogwarts. Dumbledore saw through you when you were at school and he still frightens you now, wherever you're hiding these days."

The smile had gone from Riddle's face, to be replaced by a very ugly look. "Dumbledore's been driven out of this castle by the mere memory of me!" he hissed.

"He's not as gone as you might think!" retorted Harry.

"ENOUGH!" shouted Riddle. He closed his eyes for a moment, breathing in deeply. Then he opened them again, and fixed a broad smile on his face. "To business, Harry," he said. "Twice – in your past, in my future – we have met. And twice I failed to kill you. How did you survive? Tell me everything. The longer you talk," he added softly, "the longer you stay alive."

'And the closer Ginny is to death,' thought Lena, noticing that Riddle's outline was becoming more and more distinct. She could tell that Harry was thinking the same thing.

"No one knows why you lost your powers when you attacked me," said Harry abruptly. "I don't know myself. But I know why you couldn't kill me. Because my mother died to save me. My common Muggle-born mother. She stopped you killing me."

Lena knew this already – it was something Harry had told her a few weeks ago. It had certainly been a surprise that the answer to a question that the Wizarding world had been asking for years was such a simple piece of magic. Simple, yes, but extraordinarily powerful and, in truth, quite rare in practice.

But Harry hadn't finished yet. "And I've seen the real you. I saw you last year. You're a wreck. You're barely alive. That's where your power got you. You're in hiding. You're ugly, you're foul!"

Riddle's face contorted. Then he forced it into an awful smile. "So, your mother died to save you. Yes, that's a powerful counter-charm. I can see now – there is nothing special about you, after all. I wondered, you see. Because there are strange likenesses between us, Harry Potter. Even you must have noticed. Both half-bloods, orphans, raised by Muggles. Probably the only two Parselmouths to come to Hogwarts since the great Slytherin himself. We even look something alike... but after all, it was merely a lucky chance that saved you from me. That's all I wanted to know." His smile widened. "Now, Harry, I'm going to teach you a little lesson. Let's match the powers of Lord Voldemort, heir of Salazar Slytherin, against the famous Harry Potter."

Riddle moved so he was standing directly in front of the Slytherin statue and looked up at the stone face, high above him in the half-darkness, and hissed.

Lena stared up at the statue with a morbid fascination. Slytherin's gigantic stone face was moving. His mouth opened wider and wider, to make a huge black hole.

And something was stirring inside it. Something was slithering up from the depths.

Fear washed over Lena, and she shut her eyes tight. Frantically, she tried to push herself up off the ground, but her body was still weak. Then, just as she heard the Basilisk hit the ground, she felt a pair of hands firmly grip her upper-arms and pull her up.

"I won't let it look at you," Riddle murmured. He let go of her arms. Instead, one of his hands captured her jaw and gently turned her head to the side. "You can open your eyes now."

Lena hesitated, listening to the sound of the Basilisk sliding along the floor. Once she was sure the noise was coming from the other side of the Chamber, she opened her eyes. In her peripheral vision, she could see that Riddle was standing right next to her, so close that they were practically touching. She strained her ears for any sound of Harry, but the only thing she heard was the slithering of the Basilisk's heavy body.

"Was Potter right?"

Riddle moved into Lena's direct line of vision, his eyes once again curious. His voice was low, barely above a whisper.

"About what?" replied Lena.

"About me being your father." He sounded almost nervous. "I mean, it's not like our appearances are dissimilar, and you are–"

"No," said Lena firmly, cutting him off.

There was a pause before Riddle asked, "You're sure?"

"Positive."

Riddle nodded slowly, and the corners of his lips turned up slightly.

It didn't escape Lena's notice. "You seem... pleased."

"Well, I must confess, now I've met you, I was rather hoping for a relationship of a different sort of... intimacy." His eyes flicked to behind Lena, and he began to laugh. Lena assumed he was watching Harry blindly attempt to run away from the Basilisk.

She bit her lip anxiously. She wanted to do something to help Harry, but what? Like a three-headed dog, a Basilisk was impervious to all curses – even a Killing Curse. A rooster's cry would be fatal, but Lena had no idea how create a magical replica of that – or if it would even work. Possibly if something was big and heavy enough it could crush it, but Lena suspected that nothing short of bringing down the entire Chamber of Secrets upon the Basilisk would work. And even if she had the strength to do that now, there would be an exceptionally high probability of such a collapse killing Harry as well.

Suddenly, there was a loud, almost explosive sound, and Riddle's face changed to an expression of fury. Then Lena heard an angry hissing and wild thrashing.

"No!" cried Riddle, enraged, and Lena, unable to restrain herself, risked a glance behind her.

The enormous serpent – bright, poisonous green, thick as an oak trunk – had raised itself high in the air and its great blunt head was weaving drunkenly between the pillars. And then Lena saw what had made the Basilisk stop its attack on Harry.

There was some sort of bird, its plumage red and gold, soaring around its head, and the Basilisk was snapping furiously at it with fangs long and thin as sabres. Lena blinked, perplexed. Was that a phoenix? It certainly looked like one. But how was it here? And why?

Then she recalled one of the Hogwarts house-elves telling her that Dumbledore owned (if that was the appropriate term) a phoenix, which resided in his office.

And apparently it was also an ally of Harry's. The phoenix dived. Its long, golden beak sank out of sight and a sudden shower of dark blood spattered the floor. The snake's tail thrashed, narrowly missing Harry. Lena saw that its eyes had been punctured by the phoenix; blood was streaming to the floor and the snake was spitting in agony.

Riddle strode past Lena, half-hissing, half-screaming at the now blinded Basilisk. The phoenix piped an eerie song that made the hairs on the back of Lena's neck stand on end. But her attention was momentarily drawn away from the two creatures' battle when she noticed something on the Chamber floor that had not been there before. She squinted at the object. It was hard to tell, but it appeared to be made of black cloth. Starting towards it, Lena had to throw herself out of the way when the Basilisk's tale whipped across the floor.

She hit the stone ground, rolling several yards due to the sudden momentum. Wincing, she came to a stop, then struggled to her feet. She looked over to Harry to check that he was still alive. Her relief that he was, however, was somewhat surpassed by her bewilderment at what was on his head.

Although there was some distance between her and Harry, Lena could have sworn it was the Sorting Hat.

Then the Basilisk's tail swiped across the Chamber again. This time, it hit one of the pillars that had already been damaged by Lena's uncontrolled magic, and there was an explosion of rock.

It took about half a second for Lena to realise that the trajectory of one of the larger pieces, about the size of a classroom desk, meant it was heading straight towards Ginny. Desperately, she threw her hands out in an effort to magically catch it.

Less than two feet above Ginny, the rock came to a sudden stop, suspended in mid-air. But Lena could not yet sigh in relief. All her energy was entirely focused on holding the rock; she didn't have enough to push it away from the small girl beneath it. Her whole body shook with the effort of keeping the rock from falling and crushing Ginny.

Riddle's voice suddenly came from behind her. "What are you doing?" he said sharply.

Sweat was beginning to pour down Lena's face. "She doesn't have to die."

"She does if I want to live." He was standing next to her now, his eyes narrowed.

"You already are. Lord Voldemort's still alive–"

"But I want to live." There was a distinct petulance to his voice that undercut its anger. He seemed to realise this, and changed tactics. "Consider what you could have, Lena," he said, low and seductive. "With me." He lightly touched her shoulder, then trailed his finger down her back, whispering, "Think of what we could do, what we could accomplish... together."

She and Riddle working together, pushing the boundaries of magical knowledge further than anyone else had done before... the possibilities seemed endless. It had once been her dream, but with Voldemort, her Lord Voldemort, instead. But he was so much older than her, knew so much more than her – surely he would never see her as an equal. But maybe this younger version would... all she had to do to find out was just let go, and let Ginny die...

The exertion of keeping the rock in the air made Lena's voice tremble. "It wouldn't be worth her life."

"Pathetic," snapped Riddle. Contempt practically radiated off him. "You could be so powerful, so great. Instead, you allow weakness to hold you back."

That incensed Lena. "I'm not weak," she snarled.

"Prove it," whispered Riddle, leaning into her, so that his mouth was only an inch away from her ear. "Prove to me you're not weak, and let her die."

She looked behind her to see if Harry was still all right. When she laid eyes on him, she nearly dropped the rock in shock.

He appeared to be fighting off the Basilisk. With a sword.

Not allowing herself to be side-tracked by wondering from just where the fuck Harry had obtained a sword, she turned her head so she was looking Riddle directly in the eye. "Compassion isn't weakness."

Riddle took several steps back. He stared at her, clearly perturbed. At last, he said, "You're not who I thought you were."

The disappointment and disgust in his voice sent a pang through Lena's heart. She was so unused to hearing them directed at her. She turned her gaze away from Riddle, and found herself looking at Ginny. A lonely, little girl whose only crime was wanting someone to listen to her. And now she was expected to pay the ultimate price for that.

So Lena made her choice.

She smiled at Riddle. "No. I'm better."

Then with every ounce of strength she could muster, she threw the rock at the Basilisk's head.

It crashed into the snake's jaw, causing the beast to rear its head and shriek in pain. Something clattered to the floor – half of a fang, broken by the rock.

Harry took the momentary respite to prepare himself, and when the Basilisk blindly lunged at him once more, he drove the sword into the roof of the serpent's mouth.

Riddle roared in dismay as the Basilisk keeled over sideways and fell, twitching. Lena, reinvigorated, used the temporary distraction as an opportunity to Summon her wand from his pocket.

The moment she caught it, Lena felt her strength double. Riddle spun around to face her, and roared again upon seeing the wand in her hand. A manic look on his face, he drew Harry's wand from his pocket and aimed it at its owner, screaming, "AVADA–"

"EXPELLIARMUS!" bellowed Lena, drowning out Riddle before he could finish the Killing Curse. The wand flew out of Riddle's hand and straight to Lena, who caught it. Holding her and Harry's wands in the same hand, she pointed both of them at the diary, then swung them towards Harry.

The diary took flight, zooming through the air, and landed, open, at Harry's feet.

"STAB IT!" she yelled.

Harry didn't question the command. He gripped the hilt of the sword in both hands and plunged its blade – now coated in Basilisk venom – into the heart of the book.

There was one fleeting moment in which Lena and Riddle locked eyes. And in that briefest of times, Lena saw two emotions flicker across his face.

The first was betrayal.

The second was fear.

Then there was a long, dreadful, piercing scream. Ink spurted out of the diary in torrents, flooding the floor. Riddle was writhing and twisting, screaming and flailing and then...

The Chamber was silent, except for the steady drip drip of ink still oozing from the diary.

Tom Riddle was no more.