Warning: May be slightly AU. I've only seen ninety-something episodes, and the last I saw of these two, Itachi had laid them both out flatter than a bathmat. I don't know how they get cured or whatever, this story just popped into my head and I had to write it down. So go ahead and judge me if you want, though you won't get pie.

"Kakashi-sensei?"

The silver-haired jonin turned his head on his pillow to look at the occupant of the next bed. Sasuke Uchiha was lying on his back, staring up at the ceiling with his customary emotionless expression, though Kakashi could tell by the way his right hand was clenched on the coverlet that something was bothering the boy.

"What is it, Sasuke?"

The younger shinobi looked over at his sensei, a deep furrow creasing his brow. "Am I weak?"

Kakashi blinked. Whatever he had been expecting, it wasn't this. Caught off guard, it took a moment before he answered. "Of course you're not weak. Why do you ask?" His companion looked back at the ceiling again, opening his fist and staring at the nail marks that latticed his palm.

"Itachi said I was weak, and the more I think about it...the more I believe he was right." He closed his eyes, his frown deepening. "Half my life I've spent fostering my hatred for him, thinking it was making me stronger, hoping that when I met him again, it would be enough for me to kill him. It was my purpose in life - I thought... I thought that having a purpose would give me power, power enough to defeat my brother." Sasuke opened his eyes again, clenching and unclenching the hand that wasn't wrapped in bandages, his voice dripping with disgust. "All that time, all that training, and it took him all of two minutes to take me down. He tortured you for three days straight before you fell - I couldn't even stand up to him for five minutes."

Kakashi was silent again, contemplating his student for a time. Eventually, he turned onto his side, grunting as his body was momentarily wracked with pain, and raised himself onto one elbow, fixing the boy with a steely gaze out of his one dark eye. "Listen to me, Sasuke," he said, his voice gentle but firm, "you are not weak. You are young, inexperienced, and you have not yet fully mastered your sharingan. Itachi has the advantage over you in all these areas, but that doesn't mean you're not good. You are good - phenomenal, even. It's just that Itachi is better. He's older, he's had more time and opportunity to hone his skills." The jonin coughed and slowly lowered himself back onto the soft mattress, but he didn't tear his gaze away from his one remaining pupil. "Give yourself more time. One of these days, you'll face him again, and you will win. Just give it time." Sasuke looked unconvinced.

"But Itachi-"

"Itachi knows to strike where it will hurt the most, and he knows where that is every time he faces an opponent. You've endured far too much physical pain to be much swayed by it, so it wouldn't have done him any good to put you through the same trick he used on me." He paused a moment, his breath catching silently as the memory came back to him: Shackled to the wooden gibbet, helpless, as Uchiha's sword slid in and out of his body half a dozen times before his calm, emotionless voice issued from the depths of his robe.

'Only seventy-one hours, fifty-nine minutes, and fifty-nine seconds to go.'

Seventy-two hours of the same thing, over and over, unable to escape, unable to die...

Kakashi shook off the chilling recollection and continued what he was saying, barely missing a beat. "By attacking your psyche and resurrecting your most painful memory, your brother tortured you far more efficiently than he would have any other way. So really, it's not that you're weak at all, it's more like you're too strong. Everyone has a vulnerable spot, though, and Itachi knows where - and how - to find the gap in the armor, and exploit it to the fullest. Besides," he added, "you were already physically wounded, so they tell me, which naturally made it more difficult to defend against his attack."

The boy didn't reply for a moment, but the injured jonin thought he saw a faint misting of tears in the deep black eyes. When Sasuke finally spoke, it was in a whisper that was barely audible, and Kakashi had to strain to hear him. "But he did it so easily.. All it took was a few seconds of reliving the same memory, and I collapsed like a baby.."

"A few seconds in the real world, perhaps, but your brother can control time and space when he uses that particular sharingan. It's true that he spent three days using me as a pincushion, but when he released the illusion, scarcely a minute had passed in the real world. So it may have been only a few seconds in reality, but in your head, he could have stretched it for a decade, and you wouldn't have been able to tell."

Silence rained between them, and Kakashi closed his eye, relaxing back onto the pillow. Though he tried to make light of his ordeal in front of Sasuke, being used as a pincushion for seventy-two hours straight left him completely spent.

Trust me, Sasuke, he thought, a grim, mirthless smile stretching his lips beneath the mask, you are no weaker than I am. I spent so much time building up immunity to mental and emotional pain, the attack Itachi used on you would have almost no effect. But I neglected to build resilience to physical pain. I relied too much on my training to defeat my opponents, and it served me well - until I met your brother.

Sasuke's voice shook him from his somewhat morbid train of thought, and the ninja master was relieved to hear the stern hardness renewed in the others' low tone.

"I will not lose to him again. I will grow stronger, I will grow more powerful, until I can take him down. He made me into an avenger, and I will avenge, if it takes me the rest of my life!" His hands were clenched again, both of them this time, and he seemed unaware of the pain that throbbed through his broken left wrist. His eyes were smouldering, and Kakashi could almost see Orochimaru's curse mark dancing a gleeful little jig on the boy's shoulder. His face grew worried, though he kept his voice calm.

"I haven't a doubt in the world. But remember Sasuke, to truly avenge your family, you must grow to your full potential and strength on your own. To be trained is one thing, but to accept power itself from another would not be right. They would be exacting the revenge as well, even though they would have no claim on your brother's life. Remember that on your path for vengeance."

Sasuke turned his head on his pillow, his bleak gaze seeming to bore right through his sensei without even seeing him. His next words, uttered in a low, iron-ridged tone, chilled the jonin's blood.

"I will do whatever I deem necessary to kill Itachi Uchiha. I don't care how I do it, as long as it is done.

"I will not lose to him again."