Aqua and Ignus stepped out of the cave to a sandy bluff overlooking towering breakers. The sun shone down brightly, but the wooden structures were collapsed and dark-looking plants grew between the trees.

"This is…where I met those children." Aqua whispered.

"So many worlds have been lost. Now they're all trapped here in the dark." Ignus shook his head to clear it. "You know this place, Aqua?"

"Yes, I visited once. And I met two boys I considered passing the keyblade on to. But because Terra had already given one of them the power, I didn't."

Ignus started. "Aqua. What were the boys' names?"

"They were…Sora and Riku."

"We must be getting warm." Ignus began to scan the cliffs.

"Huh?"

"There are two boys who were working to help me close the doors. Their names are Sora and Riku."

"The same boys?"

"I think so. This is where they first got the keyblade of light, so I figure there's a chance its counterpart is here too." His vision zeroed in on a cave in the cliffs. "It would make sense for the keyblade of darkness to be on the dark side of the world where the keyblade of light was, right?"

A loud boom sounded and the ground shook under them.

"Guess we'd better hurry. Come on!" Ignus ran for the cave.

As they approached it, a massive tide of Heartless exploded out, forcing the two keyblade wielders to jump out of the way. Ignus and Aqua drew their keyblades as the spiraling wave circled overhead.

(Fight Scene song: I'm the One)

As the last of the Heartless faded into nothing, the pair let their weapons vanish.

"You certainly haven't gotten rusty." Ignus smirked. "We should keep going."

Aqua nodded and they headed into the cave. In the back was a large wooden door.

"Give me a hand." Ignus put his shoulder against it and Aqua helped him push the door open. In the middle of the room beyond floated a golden keyblade.

"Is that what you're after?"

"Well, I'm still going to be fighting with Spark and Inferno, but if I'm going to seal that door…"he reached out and took the key. "Only one will do."

"A keyblade of darkness…" Aqua muttered.

"The door of darkness, tied by two keys. The door of darkness, to seal the light." Ignus recited. "Well, we've got the keys. Now we need the people to close the door."

"Sorry?"

"The door between the two realms is just spilling out darkness right now. We'll need the two keyblades, but also help on both sides to shut it."

"Well, if you'll be doing the locking, let me be the one to close the door." Aqua suggested.

"Absolutely not." Ignus said sharply. He breathed and composed himself. "I'm not trapping you down here again. Besides, the job's already taken."

Before Aqua could ask, the cavern shook with another booming sound. A bright light enveloped them, blinding them both.

Notes:

I'm the One: watch?v=B5yY4aGqUsc