The first time Uchiha Sasuke felt fear was when he saw his brother standing over the bodies of their dead parents, staring at him as if he were a stranger. He pulled through this and it made him stronger.
The second time was in the forest of death, when he was caught in one of Orochimaru's most horrifying genjutsus. He pulled through this and it made him stronger.
Sasuke stood at the climax of his story. This was what his brief life had all been leading up to. This single moment was what the avenger had forsaken his would be friends and village for, had put up with the snake sannin for, and had cut away every semblance of humanity of himself for. This was his moment, his hour, his day, to resolve everything. He never thought further ahead than this. This one small slice out of time could sum up the words Uchiha Sasuke.
In the darkness of the Uchiha meeting room he could make out the form of a figure on the throne across from him. He knew who it was. The anger swelled up inside of him threatening to burst, but he bit it back and kept silent. Uchihas were not ones to throw petty insults. He knew how this battle would go. First they would test each other's strength of mind, then body.
"So you came," said a deep voice, "I knew you would. I suppose it's my fault after all for making you want to come after me, otouto."
Sasuke couldn't bite it back any more. Even he couldn't pretend around family " Damn right it's your fault, you traitor. You have no idea how much I've waited for this day. I know exactly how this will go down. I'm the winner in the end and there's nothing you can do to stop your fate, Uchiha Itachi." By now his face had twisted into a wild sadistic grin, his hands held high as if he could feel the power in his grasp.
Itachi was finished pretending as well. He smiled sadly at his little brother, "I'm sorry Sasuke, even now after all this, I cannot give you what you truly desire."
"What are you talking about. Your death has already been written."
"You are right. I will die, but not by your hands. I am already dying as we speak from something no shinobi, regardless of power, can control. Come closer, there are things I must tell you before I go."
Sasuke's mind was in turmoil. As he edged closer cautiously, he realized that Itachi spoke the truth. He was so frail and weak that he was barely sitting up straight. Disease had indeed ravaged his body although his face and voice betrayed nothing of it. Sasuke's mask slipped for a moment as pity washed over him. The man sitting in from of him was no longer the murderer of his parents who made his life hell, but his sick, pathetic brother who he couldn't help but want to take care of.
And then the moment was gone and Sasuke felt disgusted with himself. This was Uchiha Itachi he was dealing with, not a little child. He was still strong in mind if not in body and this made him a formidable foe.
"If you're trying to beg for my pity in your final hour, I'll give you none of it," he sneered, "When I kill you I want you to feel the pain I felt when you killed my soul. But I suppose I'll hear you beg first."
"Foolish otouto, you still know nothing. But it is my duty as your brother to make you understand. I was ordered to kill the clan; it was not merely to test my vessel—
"You're lying!"
Itachi rose unsteadily, a look of great sadness on his face, "You may believe me to be a heartless man, but I was pretending all these years. Know I know I'm going to die and I desperately need you to understand these things. I was ordered to murder my family. If I hadn't, someone else would have and then you would be dead too. I left you alive because you're my brother Sasuke, not because you were weak! You should never have believed you were weak; it was wrong of me to say that. Just look at me and see what too much power does to a person!"
By know you was grasping Sasuke's shoulders, yelling at him, pouring out the anguish he had felt all this time.
Sasuke threw his brother's hands off of himself. "What makes you think I'll believe you after all this time?" he asked, searching his brothers face, "tell me."
"I…have no answer," Itachi whispered, turning away.
Sasuke sighed, drained, "Well, I don't know why, but I do believe you. But I have one question, Why didn't you tell me this while you were still alive onii-san?"
Sasuke awoke in the dark as waves of emotions rolled over him, self-pity, self-loathing, but mostly loneliness.
The dream had left him aching for human comfort, he didn't care who saw him in this state. He just needed someone, anyone. "Suigetsu, where are you?" He looked around blindly, forgetting that his eyes were still bandaged from the surgery, "Juugo? Karin! Are you there? Anyone?"
And then he remembered. He had left Suigetsu and Juugo back at the five kage summit. They had probably been captured by now. Or maybe they had escaped, they were shinobi after all. As for Karin, she had been taken by Kakashi back to the leaf where she was probably being interrogated. It was his fault they were gone.
" I'm alone", he whispered and for the third time in his short, yet tragic life Sasuke felt fear.
What's there to be afraid of Sasuke, said the voice inside his head, there's no one here but you.
"Exactly."