A/N: This chapter takes place shortly after the time of 2x19, Precipice, but it actually contains a few direct quotes from 3x22, Covenant. I own neither.

Chapter 36 - Obsession

Clark was done with this fight.

It had been a long week for him. Shortly after finding out his home planet had been destroyed, he found someone who believed he was from Krypton, but it turned out to have been a misunderstanding. Then after witnessing Lex almost kill someone, he'd overheard his parents yelling and crying about it. They didn't sound like they were arguing, but it had been a long time since they'd been so distressed.

Despite his father's assurances, Clark felt more alone than ever. Things were still awkward with Lana. Things weren't great with Pete, either; his harsh comments about Lex were still fresh on Clark's mind, and he hadn't been able to bring up the issue. Even his friendship with Chloe had gotten uncomfortable—she'd been fighting with Lana about something, and then she'd wanted to talk with Clark about the possibility of aliens, and he had to shut her down. And of course, Lex still wouldn't talk to him, or to anyone in their family.

But Clark thought Lex was the one person he might be able to make things right with, and he felt he owed it to Lex to do so. Clark had lied again, even though it had been unintentional. He insisted to Lex that he couldn't read the cave symbols, not knowing that the cave had just taught him to read the symbols.

He could set the record straight if he told Lex the truth.

He didn't run his plans by his parents. He had no idea what they would say, and he didn't care. He hadn't asked their permission before telling Pete his secret, and his parents had gotten used to the idea. Even if his parents were upset, Clark couldn't imagine them doling out a punishment that was worse than the loss of Lex's friendship.

So Clark went to visit Lex that Saturday. Security wouldn't let Clark into the mansion, but this time, Clark didn't let them stop him. He sped past and jumped the fence when they weren't looking.

Lex wasn't in his study or his bedroom. Clark searched down a few hallways, peeking into the open doors, then doubled back and searched the rooms where the doors had been closed.

He sighed when he reached his starting point. The mansion was big enough that Lex could have switched rooms while Clark was searching and Clark would have missed him entirely. He didn't want to be caught using his super speed, though.

There was one room he hadn't checked. It was locked, and as many times as Clark had been over to the mansion, he was pretty sure he'd never seen the door open.

He never would have done it if he weren't so desperate to find Lex. Clark broke the lock.

Lex wasn't inside the room, but Clark could immediately see why Lex would keep it locked.

It was a dark room, lit only by a few screens. There were pictures of the cave walls, as well as of Clark and his parents. One computer screen held a rotating image of the octagonal key; another showed a repeated animated simulation of Lex's car hitting Clark on the bridge over the river. There were a few items out on display as well—Clark recognized mementos from a few of his debacles over the past couple of years, and a small sample of Kryptonite glowed behind glass. A folder sat on a table—it appeared to be his mom's medical file.

He couldn't believe he'd trusted Lex so much that he almost confided in him. How could Lex dare to condemn his family for lying when he was doing this?

"Before you jump to conclusions, Clark—"

Clark turned around to face Lex, who had just entered the room. "You told me you stopped investigating me."

"I did."

"You did? Then what is this?"

"I understand how you can think all this is about you. But in fact, it's about me."

"More lies," Clark spat.

Lex glanced around at the room. "There's so much of my own life I can't explain. I've survived countless brushes with death, and it all started with this car crash. Then your dad confirmed for me that it's all connected—my survival, the caves, the octagon, you." He shook his head. "If I'm guilty of anything, it's that I've inherited my father's eccentric curiosity for the unexplained."

"You've inherited his dishonesty."

Lex flinched. "Clark, I'm not the only one who keeps secrets. You've even told me that."

Clark stared at Lex for a long time. He could feel his blood pressure rising in his ears. "Ever since I met you, I've been defending you, making excuses for you to people like Pete. Telling them, 'You can trust Lex Luthor. He's a good guy. He's nothing like his father.' I was wrong."

Lex's voice raised. "And what about your father, Clark? Model citizen, salt of the earth—or so everyone thinks. Maybe I'm the only one who knows the truth. The Luthors don't have a monopoly on deception, Clark. In fact, I'd say the Kents have the market cornered."

It happened so fast. Clark's fist shot out and connected with Lex's mouth.

Lex whirled around with the force and clutched his face, stumbling back. He gasped, wiping blood from his lip.

Clark was gearing back for another punch when he flashed back to that time he'd walked in on Lex after his father had backhanded him. He had bled in the same place then.

Guilt joined the anger in Clark's mind. He dropped his fist and turned to go. He heard a couple of footsteps behind him, like Lex had started follow him but given up.

Martha was just wrapping up breakfast dishes when Clark came in through the side door and plunked down at the kitchen table.

His face betrayed a mix of emotions—anger, pain, guilt, conflict. His shoulders slouched, and there was blood on his knuckles.

"Clark, are you alright?" She sat down across from him, picked up his hand, and examined the marks, but quickly realized there were no cuts in his skin. Someone else's blood, then. "What happened?"

"I went to visit Lex."

She swallowed hard. "What happened? Are you hurt?"

"He . . . he betrayed us." His eyes watered. "But I think I messed up, too."

She picked up a napkin from the table, stood to wet it at the sink, then sat back down to wipe the blood away from Clark's knuckles. "Tell me about it, sweetie."

He took a deep breath. "Security wouldn't let me in, so I sped past them and searched the mansion. He wasn't in any of the open rooms, so I broke into the one that was locked, and . . . he'd filled an entire room with evidence about my secret."

It took Martha a moment to respond. She had known that not knowing the answers to his questions was bothering Lex, but she had no idea how much. She also knew he'd been investigating her family, but she didn't realize how in depth the investigations had been.

"Then he walked in, and we argued, and I . . . I told him he was like his father."

Martha's jaw dropped, her heart sinking. "W-what did he say when you asked him to explain why he had everything in that room?"

Clark's brow furrowed. "I didn't ask."

She set down the napkin. "Then how—"

"He betrayed us, Mom! He's been collecting evidence on me ever since I've been friends with him."

She nodded. "You knew about the investigations."

"He said he stopped!"

"I know, sweetie." It wasn't going to be helpful to bring up the fact that Lex probably meant he'd stopped sending private investigators after them, not that he would get rid of all evidence he encountered. Clark felt hurt and betrayed, and she needed to meet him where he was. "I know how frustrating that must be."

"I thought he was my friend."

She placed a gentle hand on his. "Did he say anything to try to explain himself?"

"He started accusing us of lying to him. Then I got really mad, and—" He swallowed hard. "I punched him. Really hard."

She took a deep breath, not wanting to ask the next question, but knowing she needed to, given her son's powers: "Is he alive?"

"Yeah. There was a little Kryptonite in the room, so I was weaker than I usually am."

Martha let out a sigh of relief. A part of her wanted to scold him right away for losing control of his anger—they'd talked to him before about how dangerous it could be to lash out, how it could lead to decisions that would ruin his life—but his emotions were already in turmoil. He was still hurting badly from what he perceived as Lex's betrayal, as well as the way Lex had insulted him; he was drowning in guilt for having lost control and hurting his friend; and she was sure some part of him was still worried about the longer-standing fight that he hadn't managed to resolve.

One thing she knew: she didn't want to handle this one alone.

"Clark, why don't you go up to your room? I'm going to talk to your father about this."

Clark's eyes widened a little. "Am I in trouble?"

"Do you think you should be?"

Clark's head hung, his eyes squeezing closed.

She reached up to touch his face lightly. "We'll be up in a few minutes."

He nodded and disappeared up the stairs.

Martha sighed and went outside to find Jonathan in the barn. "Jonathan, I need you to take a break and come inside."

He set his pitchfork against the wall. "Sure. Everything okay?"

"It's your son."

"Which one?"

"Clark. He went to visit Lex."

She told him a shorter version of what Clark had just told her, and watched his expression shift with each turn in the story.

"And he just walked in with blood on his knuckles," she finished the story. "He's up in his room waiting for you."

"Is he okay?"

"He's a little shaken."

Jonathan nodded. "Is Lex okay?"

"I doubt it. But he's alive."

Jonathan took off his work gloves. "You've talked with Clark about hitting people, haven't you?"

"I have." She let her breath out. "I'm very concerned, Jonathan. He's hurting, and I know all of this has been hard on him, but he also made a lot of mistakes here. Breaking and entering, violence . . . He needs both of us today."

Jonathan wiped the sweat from his forehead. "Alright, let's go together."