They were on a case when Dean received the invite.

It was waiting for him at the front desk of the motel where he and his father were staying. Dean never quite understood how Lex had gotten to be so good at ensuring his letters made it to Dean, considering how much they moved around. He wondered if maybe he didn't want to know.

It had been awhile since they'd talked. Neither of them were the type to pick up a phone and call for long catch-up chats; Sam was more the kind who would do that. A couple of months before, Lex had sent a letter about a meteor-related case that he thought might involve monsters, and he'd briefly mentioned his girlfriend, but Dean had had no idea it was serious.

Dean would have said the last thing he was expecting was a wedding invitation, but what he received was even more unexpected. It was a request to be a groomsman.

Dean had never expected to have that honor in his life. Sam was the only one who might have asked him. A year ago, it wouldn't have been possible because they were both hunters, and hunters didn't marry. And now, Dean hadn't heard from Sam since he'd taken off for Stanford. He'd tried to call a couple of times in the beginning, but Sam never picked up.

It took a little convincing to get his father to let him head out to Kansas—conveniently, the number of mutant cases in Smallville never really slowed down, though they were never reported in conventional newspapers and they always seemed to resolve themselves within the week—but he was able to make it out in time to be there a couple of days early. There really wouldn't be time for a proper bachelor party, but he could at least get a suit fitted. Lex wasn't letting him pay for anything, of course.

Dean pulled up to the mansion and into the parking garage underneath—Lex's collection of cars had actually shrunk a little. He walked up to Lex's study, wondering if Sam would be at the wedding. He was sure Clark would be; it would be good to see him, too.

Lex was waiting for Dean in the study with a smiling brunette woman who absolutely would have been Dean's first pick at a bar, if it weren't for the fact that she was off-limits. Dean had never seen Lex glowing so brightly. "Dean," he said.

"Luthor. Good to see you." Dean nodded to Lex, then looked to the woman. "And you must be Helen."

"Dean. It's a pleasure to meet you, I've heard so much about you."

Dean smiled, wishing he could say the same about her.

"Your room is ready for you, if you'd like to get unpacked," Lex said.

"Ah, aren't we meeting with the tailor?" Dean asked.

"Uh, actually, I rescheduled him for tomorrow. Wanted to give you a chance to connect with the other groomsman. He should be here any minute."

Singular. So it was just Clark. Dean breathed a sigh of relief.

Then a servant opened the door to the study again, and Sam walked in.

Sam's eyes locked on Dean, immediately narrowing, though it looked more like pain than anger.

"Sam." Lex gave Sam the same broad smile he had given Dean. "How's Stanford?"

Sam brought his eyes over to Lex for only a moment before he looked back at Dean. "It's good. Keeps me busy."

"Good to hear." Lex took a glance at his phone, then he turned to Helen. "Oh, ah, Helen, we have that appointment with the, uh . . ."

She glanced from Sam, to Dean, then back to Lex. "Florist." She smirked.

"We'll be back in a little while. Give you two some time to catch up." Lex clapped Sam and Dean each on the arm, then he took Helen's arm and walked her out of the study.

Dean had wanted this chance to talk to Sam face-to-face all year. But he didn't expect it to go well. Luthor had had no right to try to force them to talk things out like that. He had no right to butt in at all. Dean made a mental note to slug him when the wedding was over.

Dean swallowed and said, "Sammy."

"It's Sam." His jaw pulsed.

"Right." Dean shifted his weight. "Ah, are you staying here at the mansion?"

"At the farm."

"Oh." That made sense. Sam had always been closer to the Kents.

"Um . . . how's Dad doing?"

"Ah, you know Dad."

"Yeah. I guess I do." Sam's nostrils flared. "Look, ah . . . This is a really important time for Lex, okay? I don't want to fight."

Something about the way Sam said it rubbed Dean the wrong way. "You don't wanna fight."

"Dean . . ."

"Is that why you think I've been trying to call you? To fight?"

"You haven't tried to call in over 10 months."

"Yeah, well, you made your position on that pretty clear."

"So did you. When you let that bastard kick me out."

"Let him . . ." Dean didn't know what fight Sam had been watching. He breathed in to start yelling, but Sam was right. This was an important week for Lex.

Sam seem to be taking deep breath's as well. "I'm gonna go to the farm. See if you can get Lex to set up separate tailoring appointments, okay?"

"Yeah."

Sam paused for one more moment, as if he wanted to say something, and then he left.

Dean paced a couple of steps and kicked the wall, then grunted and knelt down to rub his foot.

-------

Sam's blood pressure hadn't quite settled by the time he arrived at the farm.

The hug and warm lunch from Aunt Martha meant a lot. So did the long conversation with Uncle Jon about Stanford, and the guest room, already set for him, though they had to move a few baby supplies into the new nursery—Sam couldn't believe Clark was going to have two new baby siblings. He wished the wedding had been a few months later, so he could have met them.

Once he had settled in a little, Sam met Clark in the barn, up in his loft. Clark had called Sam around the time Sam had received the invitation to be Lex's groomsman. He almost hadn't gone—he really didn't want to have to see Dean right now, and exams were coming up—but between wanting to be there for Lex's big day and the urgency in Clark's voice, he didn't see that he had much of a choice.

"What's the gig?" Sam asked after checking to make sure the coast was clear and they wouldn't be overheard.

"A couple of nights ago, I started . . . hearing from my ship."

"Your ship? As in—"

"Yeah." Clark swallowed. "Apparently, there's a sort of . . . stored version of my biological father in the ship's computer."

"Like an AI."

"I guess. But a little more than that."

Clark started to unbutton his shirt, revealing a huge swollen red burn in the shape of a family crest with what appeared to be a figure 8 in the center. Sam winced just looking at it. "He did that to you?"

"He wants me to follow some destiny he's set for me. I don't know what he wants me to do, but . . ." Clark looked down at his chest. "I know what happens if I disobey."

Sam could understand why Clark had called. If the ship had the power to do that to Clark, it might come after his family next. "Clark, I don't know how to kill an AI."

"I know. I want to destroy the ship."

Sam blinked. "Uh. Isn't it indestructible?" Like you?

"I don't think so. A few months ago, I was stuck down here with a piece of kryptonite—"

"Wait, wait. Kryptonite?"

"Meteor rock. It's from my planet."

Sam would need to get caught up on the rest of this later. "Okay."

"I was stuck down here with a piece of kryptonite tied to my neck, and the ship neutralized it. Turned it white, so it didn't hurt anymore. At first I thought it was trying to protect me, but now I wonder if it was trying to protect itself."

"You think it has the same weakness you do."

Clark paced a few steps. "Earlier this school year, I kind of stumbled into these Native American caves underground. They knew everything about me, I was like a legend in their culture, and the symbols on the wall are in my native language."

"Wow. That must have been amazing."

"Yeah, well, I wasn't the only one who thought so. Lex got involved, and so did his father."

"But Lex could protect you."

Clark frowned. "Lex and I . . . haven't been on the best terms since he tried to investigate me."

"Wait, you haven't told him your secret?"

"I can't trust him."

Sam thought that was a little rich, considering the number of times he'd watched Clark lie combined with the number of times they'd all saved each other's lives. But again, it was something they could catch up on once the danger had passed. "We'll talk about it later. What do the caves have to do with all of this?"

"Well, there was this octagonal key that fit into the wall of the key, and it also fit into my ship. Lex got ahold of it, and Lionel started trying to build a duplicate, out of—"

"Kryptonite." Sam didn't like where this was going.

Clark nodded.

"You want to get that key and put it in your ship."

Clark just stared at him, the answer clear in his eyes."

"Clark . . ." Sam shook his head. "You have no idea what that will do to the ship. Or to you."

"I know. But that's a chance I have to take." Clark's eyes begged. "I need your help stealing that key."

Sam really didn't like this. He knew all too well what happened when he and Dean had gone into a fight without fully researching all of the possible outcomes, and this felt a lot like that. For all he knew, the ship might be connected to Clark; destroying the ship could kill him. It could signal some alien civilization to declare war on Earth. It could detonate a nuclear bomb in the ship. Or it could do something he couldn't even imagine.

"Sam. Please."

"Clark, I really don't think it's a good idea."

Clark's jaw set. "I'm going to head back inside," he said.

Sam knew how that felt, being shut down. Clark would need some time to cool off. "Okay," he said. "I'm going to take a walk. See you later?"

"Yeah," Clark said, but he didn't look back as he headed back into the house.