Riku filled up with rage as Sora ran through the hut to the bridge. He never got angry at Sora, even though they fought over Kairi. But he felt as mad as ever. He thought of Kairi and what the heck happened to her…and possibly her heart. But besides his Kairi-Sora problem, he had a craving ever since he saw the black ball hovering right over him. He's wanted power over Sora, gain of Kairi and her heart, and…darkness for something he doesn't even know. He quickly went back to his senses as Sora was running toward him. Riku was ready.
Riku saw Sora's heavy breathing and misunderstanding for what was happening. He was always an idiot, a voice said in Riku's head. NO! He's just Sora and all of us will eventually get out of this island, with Kairi, he responded in his head. Sora ran until he could finally get in earshot of Riku.
"Where's Kairi! I thought she was with you!"
At that moment, the darkness in Riku took over him, and explained all that he needed to know about the "doors" of other worlds.
"The door, has opened...," the darkness said through Riku, but he quickly took over it and knew what he needed to say.
"What?" Sora asked stupidly.
"The door has opened, Sora! Now we can go to the outside world!"
"What are you talking about! We've gotta find Kairi!"
"Kairi's coming with us!"
Riku couldn't stand it anymore. He couldn't stand the confusion and shock on Sora's dumb face. He had to tell him. He always had to tell him.
"Once we step through, we might not be able to come back. We may never be able to see our parents again. There's no turning back. But this may be our only chance. We can't let fear stop us! I'm not afraid of the darkness!"
On cue, he held out his right hand, inviting Sora to feel the darkness. As he said that final word, he triggered something in himself. He couldn't fight it anymore. The darkness took over him.
"Riku…," Sora said with fear.
All of a sudden, black darkness took Riku from his feet, slowly going around his body like vines or branches. He wasn't scared. Riku still held out his hand. Then he watched as the darkness got Sora. He struggled to get to Riku, determined to bring Riku back. Then, he reached Riku's hand. All went pitch black. Riku was traveling through darkness.