So this was Lex's dad.

For some reason, Dean had always pictured him bald. The man was anything but. Long, scraggly hair, expensive suit, eyes of steel. Dean was thankful to finally know what Lex's father looked like. Now, if he ever met the man in real life, he could kill him.

That was, if they got out of this alive.

"Son," the ghost said to Lex.

Lex swallowed hard. "Dad."

Released from his trance, Dean bolted for the fireplace and grabbed an iron poker. He ran back and swung. Iron didn't kill ghosts, but it sent them away, at least for a little while. The poker would pass right through the ghost, which would disappear in a puff of smoke and then materialize again a few moments later.

Instead, the poker thudded against his arm.

Dean's breath caught. That had never happened with a ghost. Never.

The ghost raised his hand, and Dean felt himself being thrown back. He slammed into the wall, his head cracking hard against the surface. Dizzily, he pulled himself to his feet.

Lex's father hadn't even stopped to look back at Dean. He took a step toward Lex. "There's not a day I don't wish you were the one who had died."

"I know," Lex said softly. "I wish the same."

This ghost was too powerful. It matched the profile of Charles Leery, and the lore checked out. But Dean had never met a ghost that could take the forms of different people, or that could withstand an iron rod.

Dean tried to remember everything Sam had researched about the dead guy. Some other remains must have been left behind. Sam hadn't mentioned any other remains—come to think of it, he hadn't mentioned the compass, either. Dean wasn't even entirely sure how Lex had gotten the ghost to give him up; he seemed to have convinced it that he deserved it more than Dean did.

"So what do we do about all of this, Lex? Hm?" Lex's father said.

"I expect you have a few ideas."

Dean bolted for the salt gun. The ghost saw him running; the gun flew away from him, smashing against the wall and landing in pieces.

The ghost raised his hand over Lex's face, and Lex flinched back.

"Hey!" Dean called. "I just tried to shoot you!"

It lowered its hand long enough to look up at Dean, but he only sneered. "My concern is with my son," he said, and he turned back to Lex.

Dean's mind raced. What else did he know about Charles Leery? He'd carried a compass . . . he'd had disappointing sons . . . he'd died because his sons had abandoned him . . . his skin had melted off in the sun, according to that chick in the museum.

Two things hit Dean at once.

For one thing, it should have been obvious that he hadn't gotten all of the man's remains, and that not all of them had been cremated. If his skin had melted off, there would have been remains everywhere. His DNA was in the sand on the island; there would be no way to get all of it without burning the whole island down.

For another, Dean had never seen human skin melt off because of sunlight. He had seen skin "melted" off before, though—or at least, that was what it had looked like. It wasn't melted so much as shed. Shapeshifters shed their skin when they switched forms. Death must have given the shape shifter some additional abilities—that was never surprising—but it hadn't robbed him of the powers he'd had in life. That must be why iron didn't work.

Dean had run into ghosts, and he'd run into monsters, but he'd never run into the ghost of a monster. The rules were bound to be different. Silver killed a living shapeshifter; maybe it would get the ghost to disappear for a little while.

Dean ran instead to the nearest kitchen, frantically rummaging through the drawers and cabinets. There was silverware, but he just couldn't see Charles letting him get close enough to stab him with that, and besides, he was pretty sure it wasn't pure silver. There was a ladle that looked almost shiny enough to be silver, but again, he highly doubted it was. Most cookware just wasn't silver.

But maybe Dean had something.

He bolted for his own room and went into his closet for his second suitcase—the one with the small arsenal. He threw aside guns—the ghost had smashed the only one loaded with salt—and dug deep into the bag. Did he still have it? Come on, come on . . . Yes, he did. The silver knife from their first fight, the one that had been dipped in lamb's blood and then later in Lex's. It had long since been cleaned; it was pure silver now.

Dean snatched up the knife, then he ran back to the ghost—whose hand was raised over Lex's cringing figure—and swung the dagger hard.

The ghost disappeared in a puff of smoke.

-------

Lex had just squeezed his eyes shut, waiting for the blow to fall, but it never came.

"Luthor, you okay?"

Lex opened his eyes. Dean was standing there with a silver knife.

Lex forced himself to breathe normally. "I'm fine," he said. "Is it . . ."

"It'll be back. Come with me." Dean raced toward the kitchen, and Lex followed. Dean started rummaging through cabinets and drawers. "Salt, salt . . ."

"Oh. Here." Lex opened one of the pantries and took out a carton of kosher salt—he'd been in this kitchen a few times.

"That'll work." Dean knelt down on the floor and started pouring the salt out onto the floor, making a circle around them. "Stay in this circle, and it can't get to you."

"How long's that going to last?"

"Long enough for us to think. Look, I don't know how to stop this thing. I've never encountered anything like it before."

"What is it?"

"I think it's the ghost of a shapeshifter."

"Shape shifter? Really?" It was hard to predict what kinds of creatures were real and which ones were mythical. Lex had never thought to ask about shape shifters.

"Yeah. Didn't even know they could come back as ghosts."

Lex took a deep breath. If even Dean didn't know how to deal with this monster, Lex had no idea how he was going to figure it out. "Well, how do you kill a shapeshifter?"

"A living one? Silver. Either a silver bullet or knife to the heart. But a ghost? I have no idea."

"Burning the remains didn't help?"

"Shapeshifters shed their skin when they shift. I'm guessing this one left some skin somewhere on the island, long time ago. No hope of figuring out where."

"So what do we do?"

"I dunno. How did Clark get rid of the thing?"

"Cleared his own guilt. Sam did the same thing."

"Oh, great. No offense, man, but why didn't it come after you?"

"Because I suppress my guilt. Most of the time, I can't feel it." Lex winced. "I don't suppose you know how to suppress yours?"

"How do you do it?"

Lex rubbed the back of his neck. "Years of practice." That wasn't going to help Dean in the slightest.

"Great."

"Well, is there anything else we can do? Come on, you're the trained hunter!"

"Ah . . ." Dean paced. "Sometimes, sometimes you can talk them down, but you'd have to know exactly what to say, and there's no way to—"

The ghost materialized a few feet in front of the salt circle. It looked so much like Lex's father, he couldn't help but cringe at the all-too-familiar look of disapproval. "Alexander Luthor," he said. "Get over here right now."

Lex took a step back. Dean held an arm out, as though to block Lex from going; Lex had no idea why Dean would think he would leave the circle.

"Lex, I'm warning you. I'll add another stroke for every second you make me wait."

A wave of anger passed over him. "You're going to kill me anyway! What difference does it make?"

"You misunderstand me, son. Keep me waiting, and I'll kill you slower."

Lex swallowed, and Dean bolted out of the circle and slashed through the ghost again with the silver knife. Then he ran back to the circle.

"This isn't a permanent solution," Lex hissed.

"I know! I'm trying to think!"

Lex took a deep breath and turned away from Dean. Now that his father wasn't in the room terrorizing him, he felt like he could finally think clearly. "What do ghosts want?"

"Ah, g-ghosts are . . . spirits that can't move on. Usually, it's some kind of unfinished business. Makes them angry."

That, Lex had seen. "Yeah, well, this one feeds on guilt."

"Uh. I guess, yeah. But neither of us can get rid of our own."

Lex didn't want to say the other piece that was on his mind—that it wouldn't do any good even if they could. Two hotel employees had died in the past week. They needed to defeat the ghost, not run away from it. The hotel would always be full of fresh prey, sons who felt guilty for disappointing their fathers.

But maybe the monster's fuel could also be its weakness.

If Lex had been able to use guilt to redirect the ghost's anger toward himself instead of Dean, maybe he could use guilt to redirect its anger toward itself. Charles Leery had been an explorer. He'd probably left his family alone for long stretches of time; Lex wasn't surprised his sons hadn't come for him.

When the ghost appeared again, it didn't appear as John Winchester or Lionel Luthor. It appeared as a middle-aged man with peeling, sunburned skin and a beard that clearly hadn't been trimmed in ages, wearing rags that might have once been a sailor's suit.

"You're Charles Leery," Dean said.

"Both of you," he said, looking from Dean to Lex, "are miserable excuses for sons."

"You're a miserable excuse for a father," Lex said.

Charles took a step closer to the salt circle. "What did you say to me, boy?"

"You're a terrible father. You should be ashamed of yourself. If your son betrayed you, it was your own fault—you didn't care about him. It was your responsibility to look after him, and you hurt him, because you only cared about yourself. You fathers are the shame of your family, not us."

"Shame!" Charles's eyes flashed. "I'll show you shame, boy!"

Lex swallowed hard, comforting himself momentarily with the thought that the ghost couldn't get past the salt circle, but the ghost grabbed a mop bucket in the corner. It was still full of dirty water. He splashed it along the floor toward Lex and Dean, and the salt in its path dissolved.

"Run," Dean whispered, and they did.

They were lucky enough to catch the ghost off guard. Dean slashed through it with the silver knife on their way out of the kitchen, and they bolted down the hallway.

"Where?" Lex shouted

"Doesn't matter. As far as possible. Try to confuse it."

"Did you get the salt?"

"No, it won't help us now. It knows how to get past a salt line."

They scrambled into one of the extra bedrooms and slammed the door behind themselves. "Well, what do we do?" Lex asked.

"Suppress your guilt again," Dean said. "I'll let it take me."

"Dean—"

"I've never killed anyone, maybe it'll let me off with a beating. We can patch me up and keep working on this—"

"You're not helping me to feel any less guilty!"

"Oh, come on, Lex, work with me!"

"It's got me thinking about Julian, I can't . . ." Lex cut off as Dean's eyes grew wide, and Lex whirled around to see Charles standing behind him. Dean ran at him with the silver knife, but Charles was ready this time. He lifted a hand, and Dean flew back, the knife flying from his hand.

Charles backhanded Lex across the face so hard, he stumbled back. In all the adrenaline, he barely felt the pain.

"You killed your brother," Charles said.

"Julian was an accident!"

"It's still your fault! And you know it! You feel it!"

"At least I didn't abandon my sons!"

A split second later, Lex's feet came off the ground, and his back exploded with pain as he slammed against the wall.

"How dare you, boy?" the ghost said, and Lex felt his airway close up. He grabbed at his throat and struggled to breathe.

Of course. It didn't care about whether it was a good father, any more than Lex's father cared.

"I know what you did. You smothered your own brother. Well, now you're going to feel what he felt while he died."

"I—I'm sorry . . . I'm so sorry—" he managed to make out before his airway closed completely. A moment later, his head was throbbing. He was really going to die here.

"It is a son's responsibility to respect his father!"

A son's responsibility.

That was it! If only he could catch his breath . . . His eyes fell on Dean, begging.

"Hey!" Dean called out. "I abandoned my brother! On purpose!"

The pressure on Lex's throat lightened just a tiny bit, and his feet touched down on the ground, though he was still pinned against the wall.

"Yeah!" Dean was slowly pulling himself to his feet. "This guy, he never hurt anyone on purpose. He's always done the best he could, better than his best. I'm the lazy one."

The pressure on Lex's throat disappeared as Charles went after Dean, but Lex still felt like his throat was closed up. He dropped to his knees and gasped for breath.

"Insolent!" Charles shouted. "You boys have no respect for your fathers!"

Lex just managed to choke out, "Like you respected yours?"

Charles stopped mid-stride. His head slowly turned toward Lex. "What did you say?"

"You heard me," Lex said, hints of a smirk playing with the corner of his lips. "Your father. What was he like?"

"My . . . my father."

"Yeah." Lex pulled himself to his knees. "Oh, he was disappointed in you, wasn't he? Wasting away your life at sea."

"I . . . I wasn't . . ."

Lex looked over at Dean, who took a step towards the ghost. "Of course, that's no surprise. You were always the freak, weren't you?" Dean said. "From the time you were born. You were different. A shifter."

"No, no." The spirit seemed to be fading, alternating between becoming more translucent and more opaque. "It wasn't like that. It wasn't—"

"You were weak. You were lazy. You didn't care enough about your family to stay with them. What did your father have to say about it?"

"He . . . no, no, no . . ." His image flashed in and out, like he was having a hard time holding his form. The remaining pressure released from Lex's throat.

"You had no respect for him, did you?" Dean asked. "I bet you have no respect for him now."

"He didn't like you shifting." Lex figured it was a good bet. "He hated you exploring."

"If he knew you were killing?" Dean shook his head.

"I wonder," Lex said, "what your father would say if he could see you now."

Charles Leery screamed. "No! . . . No!"

"We're no more disappointing as sons as you were, Charles." Despite the pain, Lex could feel himself beginning to smile. "And that's why you're going to die."

The ghost didn't flash into another form, and he didn't go up in smoke, like had happened when Dean had struck him with silver. It was more like he melted, or dissolved into the air.

And he was gone.