When Riku drops, he never seems to be able to catch Sora. Sora is just out of his reach. He can see the outline of his body and tries to reach out to him, call his name even though no words seem to come. Once his fingers grazed Sora's sleeve, he swears they did, but then he was lost to darkness once more.
When Joshua told him the nature of this dream in Traverse Town, Riku knew that he could be right next to Sora or a million miles away from him. But all he had to believe was that his heart and Sora's heart were connected and with that he knew one day he would see Sora again. They would pass their test, they would gain their Mark of Mastery, and then it would be them against the world once more.
When Riku drops in to his slumber and Sora rises from his, there is a small window in time where they pass each other. Sora seems to barely register that he is there, but to Riku this window feels like a lifetime. He studies his friend to the last detail and tries to tell him that it will all be alright; that he is by Sora's side even when it seems like he is not.
When Riku sleeps, Ansem visits him in the darkest crevice of his heart, luring him back to the darkness. Let it overwhelm you, he says. Let it consume you like it did once before. Riku struggles eternally with Ansem, now that Ansem is forever a part of him; now that Ansem has contaminated part of his heart. Riku pushes it back, but that just makes Ansem grow more impatient and stronger. While in his slumber, Riku can still hear Sora. He can hear his friend fight his way through the seven sleeping worlds; he watches as Sora almost falls in battle, and Riku wishes more than anything to give in to darkness to gain the power and strength to save his friend.
But in The World That Never Was, when Sora is at his weakest and he struggles to wake from his dream's dream; when it looks as though Sora might succumb to the Dream Eaters and fall in to an endless sleep, the keyblade in his hand shifts reality around him, allowing Riku to surface beside his friend and connect their two blades for mere seconds to obliterate the enemy. But just like that it's all over, and Riku is plunged back in to darkness once again.
When Riku wakes, he finds Sora in The World That Never Was, dreaming fitfully. He cannot rouse his friend, no matter how hard he tries. His friend calls out his name, begging for help, begging for aide in his fight with Xemnas, but his keyblade stays still and quiet, signaling to him that Sora must do this alone.
Don't you want to help your friend? Ansem calls to him. Ignore the keyblade, listen to what your heart tells you. You can help him. You just have to will it.
No. Sora must do this. Sora is not alone, Sora has Riku there in his heart. He has Roxas there. He has Aqua, he has the King. And he has Kairi. He will not fail.
Sora prevails, but he is weak, and Xemnas has filled him with so many doubts and so much darkness that he drops in to a deep, deep sleep. This time Riku does not take his place. Riku does not pass his friend. He can only watch as Sora, out of his reach, falls in to the abyss.
Riku is falling; he doesn't know how long he has been falling, and in such darkness there seems to be no bottom. But Sora is down there, and Riku must find him. Riku must bring his heart back to the surface, to the light.
A voice, faint and weak, calls his name. The darkness shatters around him, vanishing like smoke to reveal sand between his toes, a warm breeze and the smell of the ocean attacking his senses. He opens his eyes, knowing where he is already. Destiny Islands hasn't changed much, even in his dreams. The sea breeze is sweet, but it smells artificial. It is a dream, after all.
The voice calls his name again, this time closer and louder. Riku looks to the shore to find Sora standing there knee deep in the ocean. He stares at him, smiling that smile that only Sora can muster. A smile that shines even in the darkest depths of a dream.
What Riku would not give to make this real, make this second in time last forever. It was his fault that this paradise was taken from him. His fault that Kairi was taken and used by Ansem and his horde of Heartless. His fault that Sora slept for a year alone as he watched and could do nothing to wake him. All because he gave his heart over to the darkness.
"Why here?" Riku asks Sora, who continues to let the waves wash over him. He smiles.
"I thought you might like something familiar."
Riku walks to his friend and stands with him in the water. "Kairi isn't here, though."
"She's waiting for us," Sora says, as he lays his hand on Riku's chest, right over his heart. "In here."
Riku lays his hand over Sora's, closing his eyes. "Xehanort will be here soon."
Sora turns around to face the endless ocean. "Let him come. We'll be ready for him." Sora turns his head and grins at his friend. "Right Riku?"
"Right, Sora. Together."
Sora reaches his hand out Riku. Riku hesitates. He is afraid that he will allow the darkness to take him again. There is a constant balance of light and dark churning in his heart, and ever since he has pledged to walk the road to dawn he has also promised that he would not let Sora down anymore. He would be Sora's protector. The world would turn on if Riku were to disappear, but the world would know a terrible loss if Sora's bright shining light were to be snuffed out.
Riku and Sora both make their way back on to the sand and lay down, facing the beautiful cloudless sky. They take in the smell of the land and the sound of the waves as Sora turns to face Riku.
Riku takes Sora's hand. They meet each other's eyes and share a knowing smile. "Do you think we'll ever make it back?" Sora asks, closing his eyes against the gentle breeze.
"Yes, Sora. As long as you fight for light, as long as your heart continues to be the most beautiful shining star, we will always make it back."
Sora squeezed his hand. "Are you ready?"
Riku nodded, giving Sora a heartwarming smile. "As long as I'm with you."
The two boys continued to hold on to each other as they slowly close their eyes, succumbing to Ansem's hold over their dream as it infects their beautiful island. The sand dissolves beneath them, the ocean retreats in to the black. The sky melts around them, and yet they are together and everything is as it should be.
They are still holding on to each other as they drop in to oblivion.