6.
Naruto gaped at Sasuke for several seconds. "What? Expelled—you? How did you manage to get expelled from the Academy?"
Sasuke shrugged, pulling the hat off and running a hand through his hair, wrinkling his nose at the mess it was in now. "I let a girl copy my answers on a final exam in exchange for a kiss," he explained blandly. "Everything went fine, except she told on me. There was talk of letting me back in after that, but nothing ever happened—Mizuki probably had something to do with it, he never liked me. It was all very silly, actually. Itachi thought it was hilarious; he said I should be proud, since I'm the only Uchiha to ever get himself expelled. 'An impressive feat,' he called it. Anyhow, I don't really mind not being a ninja; it's way too much work and I don't really do the whole 'fighting' thing."
Naruto was finding himself becoming more and more curious about the alternate Itachi. While he had encountered the Akatsuki in the alternate world, he had been too busy at the time to really interact with them. Even though he had deemed the alternate Itachi trustworthy enough to protect Sakura, Naruto didn't really know anything else about him and it was clear that he was much different from the missing-nin Naruto remembered.
"Naruto?" Sasuke asked after they had both gone back to looking through their respective books for a few minutes.
"Yeah?" Naruto said, not looking up as he struggled through a particularly dense paragraph.
"This world's Sasuke—were you very close to him?"
"Um...you could put it that way, I guess. We were teammates, me and him and Sakura-chan."
"Really." The alternate Sasuke sounded thoughtful. "That could explain why I'm so different from him...Madara wouldn't have wanted me to have any undue influence on the plotline he'd set up for you. The less likely I was to associate with you, the smoother things would go for him."
"That makes sense," Naruto agreed. Even if he hadn't graduated, this Sasuke was pretty smart when he managed to focus—it was too bad he never became a shinobi. "Here, have a look at this bit," he said, pushing the book across the table to Sasuke and pointing at the paragraph he had been reading.
"So...many...words..." Sasuke breathed as he scanned the page. "My brain hurts," he groaned, laying across the table (and the book) and resting his head on his arms.
"Do you think some aspirin or something would help?" Naruto asked. "There's a vending machine right by the library, I can go get some."
"Couldn't hurt," Sasuke replied, his voice a bit muffled due to the fact that he was using a book as a pillow.
Naruto pushed his chair back and stood up, then paused, still not quite sure he wanted to leave the other Sasuke by himself. "Okay, I'll be right back," he said finally. "You stay right here, don't wander off."
"'kay," Sasuke mumbled as Naruto headed for the stairs.
…...
Iruka was gone when Naruto passed through the lobby on his way to the door, to his relief. He still didn't want to leave Sasuke alone too long, however, so he ran the block-and-a-half to the nearest vending machine kiosk.
The aspirin only cost five ryo, but the aged vending machine that carried them didn't register Naruto's first payment, even when he kicked it and threatened to Rasengan it all the way to the Hokage tower. Thankfully, the second payment was successful, and Naruto pocketed the packet of aspirin before heading back up towards the library. By that time, it had been more than ten minutes, long enough that the capricious alternate Sasuke could have gotten distracted again and forgotten Naruto's warning not to wander off.
Naruto sprinted all the way back to the library, and paused to catch his breath once he made it through the sliding doors. After a few moments of rest, he checked for Sasuke's chakra upstairs before he headed there himself.
The alternate Sasuke's chakra took a little work to find; it was different from that of this world's Sasuke, lighter and milder without as much rushing force behind it. It was still recognizable as Sasuke's though, and Naruto was almost going to relax before he realized that there was another chakra signature upstairs as well.
"Kakashi-sensei!" Naruto gasped, running for the stairs. "What is he doing here?"
It only took Naruto about half a minute to climb the stairs to the second floor, but it felt like hours. He could hear scuffling sounds as he hurried through the rows of shelves to the far table where he and Sasuke had been sitting.
Kakashi-sensei doesn't know this Sasuke can't fight back! Naruto thought, ducking around a shelving ladder standing in his way. He'll really hurt him!
Finally, Naruto reached the reading area and could see what was going on with Kakashi and Sasuke. The two of them were standing behind the table, facing away from where Naruto was standing. Kakashi was holding Sasuke with one arm twisted painfully behind his back, and Sasuke was using his free hand to push away the kunai Kakashi had against his neck.
"Leave him alone, Kakashi-sensei!" Naruto shouted, running over to them.
"Naruto!" Sasuke gasped. He looked hurt and frightened, and Naruto couldn't blame him. "Why is your teacher attacking me? Make him stop!"
As soon as the alternate Sasuke started talking it was clear that he wasn't who Kakashi thought he was, but the jounin still didn't release him. "Naruto," Kakashi began in a dangerously quiet tone, "who is this person, and why is he disguised as Sasuke?"