This story is a oneshot, but I do intend on writing other stories in this same universe. So if you like where this is going, let me know, and I'll try to find a way to let people know I've posted something else in this universe. AU. I'll take requests for this universe, too. I kind of like the idea of a challenge.

Disclaimer: It's not mine. No way would Lex turn evil.

"Lex..." Clark Kent stood in the door to his study, looking nervous, and scared, like the weight of the world rested on his very young shoulders.
The millionaire stood immediately and walked over, placing a gentle hand on his shoulder, trying to alleviate some of that weight. "What's wrong, Clark?"
Clark shifted, clearly uncomfortable. "We need to talk, Lex." The farm boy looked around nervously. "Are you sure no one can hear us in here?"
Lex nodded. "I just had the place sweeped yesterday. Clark, are you alright?"
Hesitantly, he nodded. "I-I'm fine. I just feel like I need to tell you the truth. Just... I'm scared."
Gently, the millionaire led his young friend over to his couch. "Hey. You don't need to be scared to tell me anything, Clark. I promise."
Clark nodded, but he still looked petrified. "I know, and if I didn't believe that, I wouldn't be sitting here right now, Lex. I just... I can't help but be afraid. No one aside from my parents and myself know this, and it would be impossible to have kept it from them. I... I... I'm... I'm not exactly from around here, Lex."
The man was pretty sure his friend didn't mean he wasn't from Smallville. That wouldn't exactly be a huge conundrum that had him teetering on the edge of a panic attack. "What exactly do you mean by that, Clark?"
Swallowing back his fear, Clark finally choked out what he had been trying to say. "I mean I'm not from Earth."
Wide eyed, Clark stared at his friend, waiting. 'Waiting for me to scream at him in disgust, attempt to kidnap him and force him under a microscope, or waiting for me to accept him.' Lex realized. He hugged the boy, then pulled back to find a grin on Clark's face at the acceptance. "I couldn't be happier that you trusted me enough to tell me this, Clark. And I promise I will protect you."
Clark shook his head. "You don't have to do that, Lex. I'm just glad you don't hate me."
Lex held Clark's shoulders and looked him dead in the eyes, locking the young teenager in his gaze. "Clark, I could never hate you. And I will protect you. I couldn't know something like this and not at least watch out for you." As he stared at the boy he considered to be a younger brother, tears started rolling down Clark's face. "Hey. What's wrong? It's okay, Clark. I would never hurt you, and I would never let anyone else hurt you, either."
Taking a deep breath, Clark attempted to calm himself. "I just... I... I... I don't know. I just... I haven't... I've never told anyone this, Lex, and there's more to it. So much more. I.. You did hit me with your car that day. I have powers. I can do things. I have x-ray vision, and super speed, and super strength, and I'm invulnerable, and some of those powers are relatively new, so for all I know, there could be so many more I don't know about yet."
Lex shuddered at the thought of what someone like his father would do with that information. It would be so easy to take advantage of Clark. Even if his powers kept him from being physically harmed, it would be easy to get to someone as caring as him through the people he cares about, or even just people in general. "Clark... That's how you manage to be Smallville's personal hero."

Sheepishly, Smallville's resident alien nodded. "Ya. I guess you could look at it like that. I'm just doing the right thing. It's just a lot less dangerous to do."

Smiling, Lex said, "You don't give yourself enough credit."

Clark gave Lex a shaky grin. "That's what my parents keep telling me." The incredibly nervous expression made a comeback. "Lex, there's one more thing. And telling you... It'll take even more than telling you I'm not from Earth."

To say Lex was astounded would be an understatement. "What could possibly be more of a secret than that?"
"A secret that's connected to it." Clark decided to take the plunge. He was too far in, now. No going back. "I'm not totally invincible. There's one thing that can hurt me. The meteor rocks that fell with me that day... They make me sick and take away my powers. I'm pretty sure if I'm exposed to them long enough they could kill me."
Realization dawned on Lex. "That night I found you tied up in that field, wearing Lana's necklace. You couldn't do anything because it was making you sick. You could have died."
The teenager nodded. "If you hadn't come along, I'm pretty sure I would have."
Lex felt fury bubble up inside him. "You never did tell me who did that to you. And they almost killed you. Who was it, Clark? Did they know about the meteor rocks?"
Clark shook his head. "No, they didn't know about the meteor rocks. And it was the Smallville High football team. It's sort of a tradition. Lana giving Whitney her necklace for good luck was just bad luck on my part."
The millionaire grimaced. "One hell of a tradition. That's kidnapping and assault, and they should be brought up on charges for it."
"No. The tradition stopped. I was Smallville's last Scarecrow. After what it caused, that was a line no one wanted to cross anymore." Clark grinned. "Besides, I got revenge."
Intrigued, Lex raised an eyebrow. "How so?"
Chuckling evilly, Clark asked, "Did you hear about the mysteriously stacked trucks of some of the members of the football team?"
"Clark! Congratulations! I didn't expect that." Lex was grinning now, too. Even if he was far too nice to actually get the boys thrown in jail, and potentially ruin their lives, at least he stood up for himself.
The mood turned somber again when Clark's apprehension resurfaced. "So it doesn't bother you that I'm not normal? Not human..."
Lex was quick to reassure his friend. "I'll say it as many times as you need to hear it: You are the same Clark Kent that still saved my life after I almost killed you, the same Clark Kent that is my best friend. I don't care if you're from this planet or this galaxy. I will admit that my scientific curiosity is peaked though." Clark's breathing quickened, and his eyes became frantic. Lex frowned. "I wish I didn't have to repeat this one, but I will never hurt you, Clark."
Clark took a deep, soothing breath. "I know, Lex. I don't doubt that, I promise, but think about it like this. I've spent my entire life trying to hide this because of what people might do if they found out, and now I'm just putting it all out in the open."
The millionaire nodded in understanding. "I understand. This can't be easy for you. I'm sorry I've been pressuring you."
The fifteen year old blanched. "You're sorry? I'M sorry!" Clark got quiet. "It's all my fault. The meteor freaks, your hair, Lana's parents... All of it was my fault."

Lex was shocked. He took on a deadly quiet tone that he had never used on his best friend before. Usually it was used in protecting his best friend, and right now he needed to protect him from himself. "Clark Kent, you listen to me right now. No one should even consider blaming you for this, because it's not even feasible, and that goes for you, too. Based on the age you are now and the date of the meteor shower, you were no more than a toddler when you came to Earth. You couldn't control it any more than I could. And you help with more than just meteor freak problems; you've done so much for the people of Earth, and I'm sure you'll grow up to do even more. You belong here as much as anyone else."

Clark grinned. "Thanks, Lex."

Smiling slightly, Lex wrapped an arm around his young friend. "Did I ever tell you I always wanted a younger brother?"

The grin widened. "Hey, you want to come over for dinner. You know my parents are over the whole, "don't trust a Luthor" thing, but they still want to talk to you about this."

Lex nodded. "I can understand that. This is a pretty important secret. Something would be amiss if they didn't at least want to check in. I can bring you home when we leave. In the meantime, how about I kick your butt at pool?"

Having no real confidence that he would be able to win, Clark stood. "Bring it on."