Who can say if I've been changed for the better?

But, because I knew you, I have been changed for good.

"You don't have to go, idiot," John insisted, crossing his arms and glaring from across the room.

"I do, though," Sherlock responded easily. "Surely even you can see that?"

John sighed, scrubbing a hand over his face and walking a few steps closer. "It'll blow over," he claimed, shaking his head at the other boy. "You don't have to leave. Where will you go?"

"Anywhere," Sherlock vowed, shaking his own head. "I can't stay. Not when I know what's finally going on. I honestly can't believe it's taken me this long to find out," he added, walking closer to John.

"Just because the Wizard's not who you thought…" John began.

"He's evil, John. Not incompetent, not a well-meaning man, not a figurehead. He's completely evil, and we've given him complete control of Oz," Sherlock cut across John's words. "And of course Mycroft had to be involved. He knew all along. He was helping him."

"Don't leave because of this," John protested, taking the final steps to reach where Sherlock stood. "Please," he added.

"I have to," Sherlock attempted to smile, but it was completely without warmth. He sighed instead, looking John in the eyes. "John Watson. You are completely ordinary," he said.

"Thanks, mate," John snorted, looking a bit confused.

"No," Sherlock continued. "You're not, though. It took me so long to figure it out…Just because you seem ordinary doesn't mean you are," he turned his head to the side, studying John. "I don't know how to explain it," he shook his head, "but you've…changed me. No one's ever done that before. You made me love you," he added, continuing to speak, despite John's look of surprise. "I couldn't believe it. I still can't figure out if that's a strength or weakness, but, either way, you've changed me. Forever. And I wouldn't change that if I could."

"Sherlock, please don-" John begged, knowing that this was how Sherlock was choosing to say goodbye.

"I have to go. I'm sorry," he said, looking genuinely sorry for once in his life. "I'll come back some day," he promised. "You'll see." Sherlock smiled half-heartedly, starting to fade, while John gasped. The spell was starting its work. Sherlock had set it up so that he wouldn't be able to change his mind and stay after his conversation with John.

"Goodbye, John," he waved, still fading. "I love you," he added, right before he disappeared.

"No!" John yelled, seeing Sherlock gone. "You can't just-you idiot, why..?" he slumped against a wall, still staring at the spot where Sherlock had vanished and remembering his words. 'I'll come back some day. You'll see.'

Hopefully, he would.