Riku took his first tentative step off of the patch of earth on which the cave was floating. To his surprise, the air supported him well, as if he was simply walking on a flat plain of ground. The only difference was that below his feet, he could see purple swirling clouds of darkness expanding infinitely below him. The sight made his heart leap up into his throat. He took a few steps forward; dark essence splashed around his feet, but overall the path seemed to be safe.

He glanced back; the cave was just another piece of stone floating in the vast smoky abyss. He could see Kairi watching his progress anxiously; when she saw him looking, she waved, and he waved back. He had to admit, he was nervous about facing Ansem; he had never fought him head-on before, but he seemed incredibly powerful. Riku knew from his own experience how deadly the forces of darkness could be. It was almost enough to make him go back and ask for one of them, or maybe all of them, to go with him.

It occurred to him then that he was being almost idiotically calm for someone who was about to fight for the future of the entire universe. A spasm of panic ran through him. Could he even do it? What if he failed? What if he was killed, and the universe was swallowed up by darkness? What if everything - saving Kairi, coming here - was for nothing?

But don't be afraid. You hold the mightiest weapon of all.

Yes... that was right. That phrase, so long forgotten, resurfaced in his mind. He had heard it in his dream that night, hadn't he? The night before it had all happened.

So don't forget: You are the one who will open the door.

This was his purpose. He was the Keyblade Master, after all. It was his destiny, and as long as destiny was on his side he wouldn't lose. He couldn't lose... he was the world's last hope.

Holding out his hand, he summoned the Keyblade. Its light gave him some reassurance. Almost instantly, however, Heartless began to appear around him. They were unlike any he had ever seen; tall, muscled beasts with wings and dark swords that floated through the air with ease. He could nearly taste the foul aura they were giving off, not to mention the power they radiated. He was near the heart of all darkness, all right. If he sealed the Door to Darkness, would the Heartless also begin to disappear? If so, then this truly was the only way to fix all of the lives he had ruined. He had done so many horrible things, all in the name of the darkness he had used to fight for Kairi.

But not any more.

He held the Keyblade over his head, preparing for battle. As his position shifted, he felt Kairi's good luck charm move in his pocket. The feeling gave his heart warmth and strength. He would still fight for Kairi - he always would, until his last dying breath. But this time, it wasn't with darkness that he would fight for her, but with the strength of his heart alone. Somehow, against all sense and logic, he knew that it would be enough.

I will destroy them. For her.

Riku fought his way deeper and deeper into the depths of the strange, dark world. While the area he had first visited had been lit by a hazy purple glow, the dark abyss began to grow more sinister the deeper he went. He found himself now standing on a wide, circular platform, the edges of which were jagged like teeth; a plume of purple smoke rose through the center.

"What's this?" he muttered, reaching out to touch the smoke cautiously. His hand disappeared, but was unharmed. Driven by curiosity, he stuck his head through.

To his shock, he found himself surrounded by a familiar town plaza, filled with Heartless. "Is this Traverse Town?"

But how was that possible? He was in the world of darkness, not at all near the small refugee town. Unless...

Was this how the Heartless had been traveling between worlds so easily? It made sense; Riku had been able to travel from place to place using the power of darkness, but the Heartless could only go one by one using that method. The high number of Heartless that had been pouring into worlds recently must have been helped by these gateways.

Riku withdrew his head, then looked around. Outside of the circular platform, he could see many different gateways extending endlessly. He imagined that there must be one gateway for every world whose walls had broken down, opening it to darkness. Many of the gateways had gone out; were those the worlds that had been destroyed? There were so many of them...

Riku shook his head. He couldn't get distracted. This was why he was here... to save the worlds he had helped to destroy. To fix the lives he had ruined. To try to earn some kind of salvation.

More Heartless began to appear around him, and he charged onward.

Riku broke through the wall, panting. He was exhausted; the number of Heartless was only increasing, and he was finding it more difficult to fight his way through them. He seemed to be safe now, though. He found himself inside a tiny room, with small streams trickling down the walls into natural stone basins. At the far side of the room there was a door.

Riku reached out and touched the handle. Instantly, a voice began speaking to him.

Careful. This is the last haven you'll find here. Beyond, there is no light to protect you. But don't be afraid. Your heart is the mightiest weapon of all. Remember, you are the one who will open the door to the light.

That's the same voice, Riku found himself thinking. The one from my dream.

Did that mean that beyond this door was the true heart of darkness? If so, then Ansem was just ahead. He couldn't turn back now; it was time to end this.

Pulling hard on the handle, he opened the door.

To his immense surprise, he immediately found himself facing a sunny blue sky, white billowing clouds, and a sandy beach that was eerily familiar. Riku stared, shocked.

"This is... my island!"

Memories of his home began to flood his mind. Riku, Sora, and Kairi racing each other on the sand, going swimming, fighting with toy swords, playing in the secret place, catching fish, sitting on the trunk of the Paupu tree, building their raft...

The door has opened.

Slowly, the illusion began to disappear. Trees faded, cracks appeared in the sand, and the wooden bridges and docks became splintered ruins. It was as if he was witnessing the destruction of his island all over again.

This world has been connected... tied to the darkness.

The ocean waves turned from their brilliant blue into a deep, dark purple. Soon enough the water disappeared completely; Riku could see nothingness expanding infinitely around them.

If you embrace the darkness...it will be so.

The words kept springing to his mind of their own accord. That's right. This was all his fault... it was Ansem who had first come to the islands and told Riku about darkness. Riku had to destroy him, if only to repay him for everything that he had gone through.

Ansem was standing at the edge of the beach, looking out into the dark void surrounding the floating chunk of the island. Riku dashed towards him, prepared to attack, but was thrown back by an invisible force.

"Let me through!" Riku shouted. Ansem chuckled, but didn't turn around.

"You sound angry, Riku."

"Damn right I'm angry! You're the one who caused all of this!"

"No, I'm not," Ansem said calmly. He gestured around him. "Take a look at this tiny place. To the heart seeking freedom, this island is a prison surrounded by water." He chuckled, then turned to face Riku, a cruel smile on his lips. Riku's grip on the Keyblade tightened involuntarily. "And so you sought to escape from your prison. You sought a way to cross over into other worlds, and you opened your heart to darkness. The Heartless soon followed. It was because of you that all of this happened, not me."

Riku opened his mouth to protest, but nothing came out. He was bright red; somehow, he couldn't find the words to say, and he knew that Ansem was right.

"I seem to have touched on a sensitive subject," Ansem said quietly. He smirked. "Don't feel bad; it's not entirely your fault that you destroyed your home, your family, and even your best friend in your selfishness. It's perfectly natural. Your heart belongs to darkness. All worlds begin in darkness, and all so end. The heart is no different. Darkness sprouts within it, it grows, it consumes it. Such is its nature. In the end, every heart returns to the darkness whence it came."

Ansem suddenly vanished, reappearing behind him; Riku turned quickly to face him.

"You see, darkness is the heart's true essence!" Ansem said fiercely.

"That's not true!" Riku found himself shouting.

"You're one to speak," the man scoffed. He held up his hand; it glowed with dark energy. "You wanted this power, don't deny it. You did everything to gain it. The heart is weak, insubstantial, flimsy... andyours is the primary specimen! Why, you were the one who-"

Riku slashed the Keyblade through the air, cutting Ansem off. He was boiling with rage. He didn't know why... he hadn't earned the right to defend himself after everything he had done. Was it pride, denial? He had done so many horrible things, for which there was no excuse. Blaming it all on darkness would have been so easy, so logical... and yet somehow he knew that it wasn't the truth. No one and nothing was responsible for his actions but himself. Not Ansem, not this darkness, not even his feelings for Kairi. Only himself.

"I know I'm not one to speak," Riku said quietly. "You're right. I wanted that power for myself; I craved it. But that's not who I am."

"Not who you are?" Ansem said, voice dripping with scorn. "Who are you trying to fool? You have shown enormous willpower; you showed no fear in opening yourself up to the darkness. You became darkness itself!"

"I know that," Riku insisted. "I know that my heart was weak. I know that I gave in to my emotions and desires far too easily. But no more." He pulled Kairi's good luck charm from his pocket, squeezing it tenderly. "No matter how deep the darkness, a light shines within. It was that light that saved me from this twisted path. I know that now."

He returned the shell charm to his pocket, then held the Keyblade over his head, poised for battle. "I reject your darkness, Ansem!"

Ansem glared at him, then floated a few feet into the air.

"I expected more from you, Riku. I thought you were smarter than that... but apparently I was wrong. It seems that you have come this far and still you understand nothing. Every light must fade, every heart return to darkness!"

A huge Heartless suddenly appeared in midair behind Ansem; Riku recoiled as it swiped at him furiously. Riku slashed his Keyblade at Ansem, but the Heartless blocked it and grabbed Riku by the throat. Riku struggled to break free as he was lifted off of the ground, but its grip merely tightened.

"You belong to darkness!" Ansem shouted furiously.

"NO!" Riku shouted back. There was a flash of light, and the Heartless released him as if burned. Riku landed clumsily on the sandy ground, but recovered quickly and slashed at Ansem's chest. Ansem hissed in pain and fury.

"Why do you deny it?"

"Because that's not who I am!" Riku shouted, dodging another blow. The Heartless made to block his next attack, but Riku swung the Keyblade in a wide arc and brought it smashing down on the side of the Heartless' arm. A dark gash appeared where the Keyblade struck, and the Heartless recoiled in pain.

Ansem glared at him, breathing heavily. "Fine. Deny it all you wish. But I have seen what is truly within your heart. I will show you how dark and twisted it has become!"

He lifted his hand; the ground began to shake. Slowly, the huge tree at the center of their island began to split in two. It opened wide, revealing a tattered, torn cavity at the center. Riku realized that that must have been where the heart of Destiny Islands once rested. Now that it was gone, there was nothing left but a dark, hollow space. Was that really how Riku's heart looked? He shook his head stubbornly; there was a light there, he knew it. His feelings for Kairi were proof enough that his heart wasn't all dark.

Ansem drifted backwards, floating effortlessly, and Riku charged after him, ready for the final battle. As soon as he stepped into the space where the heart of the world once was, darkness suddenly enveloped them both.

Riku found himself floating in the middle of dark nothingness. What had happened? They had gone into the place where the heart of Destiny Islands had once rested; perhaps it had brought them here. But where was here?

Ansem's voice spoke out, echoing in the emptiness. "Behold the endless abyss! Within lies the heart of all worlds: Kingdom Hearts!"

For the first time, Riku saw it, and the sight took his breath away. A huge white door, more colossal than anything he had ever seen before, stood towering on a patch of land in the middle of the void. His blood ran cold. Kingdom Hearts. The Door to Darkness. Could that truly be the heart of all worlds, and the heart of all darkness? What was behind it?

"Look as hard as you are able," Ansem continued smugly. "You'll not find even the smallest glimmer of light. From those dark depths are all hearts born. Even yours."

Riku turned to face Ansem, but was shocked to see that his Heartless guardian had somehow evolved. Now, it was gigantic and monstrous, nearly as big as a world itself. Realization struck Riku painfully. All of the worlds that he and the Heartless had destroyed... this was what had happened to their hearts. They had somehow woven together to form an entire Heartless world, a World of Chaos. Dark sinews had attached themselves to Ansem's body, connecting him to it and making him one with the enormous Heartless in deadly symbiosis. Ansem glared at Riku with triumph.

"Darkness conquers all worlds!"

Riku clenched his Keyblade, prepared to fight, but he suddenly found himself unable to stand. With no ground to support him, he began to plummet down into the dark abyss. He began to panic, shutting his eyes in desperate concentration; was this really how it was going to end?

Come on, Riku! Don't tell me you're giving up already!

Riku's eyes snapped open. Sora. He had heard him. Sora was somewhere nearby. That single thought filled his heart with so much hope and light that he felt uplifted.

No, wait. He was really being uplifted. Was he... flying?

Riku soared up to face Ansem, swinging the Keyblade through the air.

"This ends here, Ansem!"

Ansem chuckled darkly. "I agree." He lifted his hands in the air and dark energy began to form. The smoky air around him seemed to be concentrating into a pulsating, radiating orb of darkness that crackled with energy. It looked just like the one that had destroyed their island.

Riku closed his eyes, then pulled Kairi's lucky charm out of his pocket, focusing every fiber of his being onto it. Sora, Kairi, and everyone else... they were all counting on him. He wouldn't let them down. The charm began to glow faintly of its own accord. He couldn't let them down. This was his salvation and his destiny.

"Why do you fear the darkness?" Ansem insisted. "You could have so much power if you simply gave in! Release your heart; help me open the Door to Darkness. You remember when you were a Heartless; do you not remember the power you held?"

"I remember, Ansem," Riku said quietly. Both the Keyblade and Kairi's charm were glowing brightly now. "That power is great. I've felt it myself."

He swung the Keyblade around, pointing it straight at the orb of dark energy hovering over Ansem. Ansem glared at him suspiciously.

"But I can't go back to the darkness, and I can't let you open that door. I have a promise to keep."

A torrent of light suddenly shot out of the end of the Keyblade, amplified ten-fold by the effect that Kairi's charm had on the light in Riku's heart. The beam pierced the dark orb; there was an ear-splitting explosion of sound, and light filled the dark void. Both Ansem and the Heartless screamed; strips of the dark creature tore away forcefully, burning off in the light. Its unearthly scream echoed in the abyss, and soon there was nothing left of it, its connection to Ansem ripped away.

Both Riku and Ansem were breathing heavily, floating in the darkness; they were all alone now.

Ansem was clutching his side in pain, but smirked. "Very well. I see that there is no use in trying to beat sense into you. But you should know that your efforts are futile. The Keyblade alone cannot seal the Door to Darkness!"

Ansem stretched out his hand, reaching for the huge white door commandingly. With a booming sound, it cracked open. Riku instinctively moved to stop him, but couldn't get any closer.

"Kingdom Hearts! Fill me with the power of darkness!" Dark wisps of smoke began to seep from the edges of the door, trailing towards Ansem. "Supreme darkness..."

Riku shook his head. Ansem was wrong, and he knew it. Hearts might contain darkness - Riku knew that better than anyone - but that wasn't what they were truly made of. His journeys had told him that much. No matter how deep the darkness, a light shines within... he knew that now. He was the prime example. Kairi had shown him that.

"You're wrong, Ansem. I know now, without a doubt... Kingdom Hearts is light!"

The door burst open, and the dark smoke was cut through with a piercing beam of brilliant light, more magnificent and warming than any Riku had ever seen before. Ansem, who had been floating directly in front of the door, was bathed in its light. He stared into it with shock.

"Wha... light? But why..."

There was a loud, brilliant explosion of light, and Ansem faded away, completely disintegrated. Riku's heart was beating fast; he could barely believe it. It was over. Ansem was gone. He had done it. There was only one thing left to do.

Riku landed on the patch of ground, then ran to the door. It was even more monumental up close. He pushed against the door with all of his might. He had to close it, and fast, before the Heartless began to move through the door. Already, Riku could see gigantic Heartless beginning to rise up from within the door. He strained forward, but the colossal door seemed barely to budge. Maybe bringing the others would have been a good idea after all. A faint spasm of panic ran through him; what if he couldn't close the door?

"I can't..." he said weakly, now sweating from the effort.

"Riku, don't give up!" a familiar voice suddenly shouted. Riku looked up in disbelief, but sure enough he saw Sora staring back at him from the other side of the door.

"S...Sora! You're alive!"

"Come on, Riku! Push! Together we can do it!"

Riku stared at the fourteen-year-old boy tugging at the edge of the white door. The boy he had grown up with, played with, dreamed with. Riku's expression turned to horror as he realized what this meant.

"But if I do that, you'll be..."

"Riku, hurry!" Sora urged. "The Heartless are coming!"

Riku found himself at a loss for words, but began to push nonetheless. From his view into Kingdom Hearts, he could see several of the huge Heartless disappearing. Suddenly a small silhouette appeared, holding aloft an inverted-colored Keyblade. Somehow, Riku felt like he knew him.

"You're... the King?" Riku asked aloud, not knowing how he knew.

"Yes," the mouse called out. "Now, Riku! Let's close this door for good!"

"Close it, quick!" Sora insisted, straining against the door, but Riku didn't obey. How could the King ask him to close the door with himself and Sora still trapped within? There was so much that he wanted to say to Sora... he had fought so hard to get back to him...

"Don't worry," the King said with a smile. "There will always be a door to the light."

Sora nodded. He looked like he was trying to be brave, but Riku could see the sadness beneath the smile. "You can trust him. It's okay... we'll find each other again. Then all three of us can go home together."

Riku hesitated, feeling his heart torn between the two decisions. Finally, he gave in. "Okay." He pushed all of his weight against the door, and Sora began to pull from the other side. Slowly, the door began to close.

Moments before the door shut completely, Sora turned to look at Riku. Tears began to fill his eyes, but he smiled. "Riku, take care of her."

Riku nodded; he had to try hard to stop himself from tearing up as well. This was it. With a final, mighty shove, the door closed with an echoing boom.

It was time. Riku jumped back, then raised the Keyblade into the air. The tip shot out a beam of brilliant light; on the other side of the door, he was sure that the King's Keyblade was doing the same. As it sealed, Kingdom Hearts began to glow brightly, then slowly it faded away, the huge white door disintegrating into nothingness. Soon there was nothing there.

Riku felt his heart stop. He had done it. The universe was safe. Everything would go back to the way it was.

Except... for Sora.

Riku stared for several moments at the place where the door had once been, an inexplicable sadness filling him.

Don't worry. There will always be a door to the light.

That's right. If there was a way to save Sora, he had to take it. Riku would do anything he could to find Sora again. Riku owed him that much after everything he had put Sora through. Going back to the islands would have to wait.

There was a faint rumbling sound. Turning, Riku scanned the area for the cause of the noise, and his eyes fell on Kairi. She was standing a good distance away; she looked confused as to how she had gotten there.

"K...Kairi!" he shouted, running towards her.

"Riku!" she said. A tremor shook the ground; Kairi fell forward, and Riku caught her arm. Sand was forming around Kairi's feet, and Riku immediately realized what was happening: the worlds were returning to their original states. The Destiny Islands were returning, and they were taking Kairi with them.

"Kairi," Riku said urgently, as she began to drift away from him. He only had a moment, he knew, and he needed to make it count. "I have to find Sora, I'm sorry. But don't forget, I'll never really be gone. Our hearts are connected, so I'm always with you. I'll come back to you, I promise!"

The patch of sand Kairi was standing on pulled further away, and soon Riku and Kairi were barely able to hold on to one another. They met each other's eyes, and a million unspoken things passed between them. Finally, Kairi smiled.

"I know you will!"

Unable to hold on any longer, Kairi's hold on his hand broke. She reached out to him as she drifted further away; though she knew that it wasn't really any use, it made her feel better to be reaching towards him. She was barely aware that more and more sand was attaching itself to the space around her; slowly, the beach of their island was forming, but Kairi's eyes were locked on Riku. Her heart ached. So much had happened between them... she didn't know what she thought any more. Riku, Sora, and Kairi... would things ever be the same between them? Even if she returned to the islands... it wouldn't be home without them.

Her thoughts were distracted as a glowing speck of light drifted down into her closed hands. Startled, she looked up, and saw with wonder that thousands of them were cascading down like some kind of enchanted snowfall. She held out her hands, astounded, trying to touch them; as the glowing snowflakes touched the ground, the plants of the island sprouted magically to life, bursting into existence around her. With a faint whisper, the ocean waves rushed up to meet her as well, filling in the waterless beach. In the distance, she could see Riku shouting something to her, but she was too far away to hear. She watched as he became obscured in the glow of Kingdom Hearts; soon he was nothing but a part of the shining aura on the horizon, far across the ocean.

Thousands of shooting starts suddenly burst from the aura, flying into the heavens and embedding themselves into the inky black sky; the worlds were all returning, coming back to life just like their island. Kairi watched the millions of stars dot the sky in hushed awe; they were beautiful. The sight made her feel happy, knowing that with every restored world there were people returning to life as well. That was including here... soon all of their friends and families would be returning, waking in the morning as if nothing had ever happened. To them, their world had never been destroyed, and tomorrow was just another day.

But not for her. Her true family would be gone for quite some time.

The next day, Kairi found herself on their island, alone, exploring its depths and thinking deeply about Sora and Riku. She couldn't explain to anyone where the two boys had gone, only saying that they were someplace far away, but that they would be back eventually. She knew that it was true... but it still hurt to wonder how long that would be.

She walked through the Secret Place, its walls filled with memories. How many lazy afternoons had they spent playing here, dreaming of new worlds and new adventures? Had their real adventures been worth it? She smiled as she looked over some of Sora and Riku's doodles; in one, the two boys were facing off against a huge monster while protecting Kairi. It made her laugh; they had both always been so protective of her. They still were...

Her eyes fell on another drawing. It was one that Sora and Kairi had drawn together, when they had been so much younger. They had drawn each other, although Sora's picture of Kairi was a lot messier than Kairi's picture of Sora. Something about the childhood portraits had changed, however.

A hand had been drawn on to the picture of Sora, reaching out to Kairi. Crudely drawn in his hand was a star shaped object, and with a rush of tears Kairi realized what it was. A Paupu fruit. The fruit that was supposed to bind two people's destinies together forever. Sora had wanted to give one to her, and from the look of it this addition couldn't be more than a day or two old. What did this mean?

Tears poured down her cheeks. She lifted her hand to the stone wall, touching the drawing tenderly. She cared about Sora so dearly, but... so much had happened lately. She felt so confused. What was she to do? Nearby, she could see the small stone that had been used to make the paupu fruit drawing, as well as all of the other drawings in the cave.

She did not pick it up.