Author's Note:

Good response so far, so thank you all for your interest, both those who reviewed and those who followed.

Thanks to aliengirlguy, Rose0, and deanssammy for their reviews on chapter 1!

Chapter 2 - Setting Up Shop

It took two days for Sam to finish the mental checklist he'd created for himself. First, he needed a base camp. His particular mission didn't necessarily warrant much moving around, and he needed to be somewhere secluded, where nobody would find him while he tested various ways of making his death permanent. He didn't need some civilian freaking out because they'd found a dead body, or worse, freaking out in the unfortunately likely event that that dead body came back to life. He settled for a cabin about thirty minutes outside a reasonable sized town in Idaho. It was secluded, he had no reason to be there, and it was only a few hours from a library that had a lot of supernatural lore, just in case he needed the resources he couldn't go to Bobby for.

Thankfully, the cabin was already set up for wireless from a previous owner, so all Sam had to do was activate it and set up his own precautions to make sure he couldn't be traced. He changed his voicemail message to inform any callers that he was off the grid, and if they had an emergency they should e-mail him, then set about setting up precautions for his e-mail so it wasn't traceable if he logged into it and checked his messages or sent any e-mails. He didn't expect to hear from Dean, but Bobby would probably get anxious if he didn't hear from Sam, so it was better to have an emergency contact method of some sort. Being off the grid didn't mean he didn't want to be in the know.

The rest of Sam's checklist included warding the cabin against anything he could think of, stocking up on sleep medication from six different drug stores at his various stops as he hitch hiked his way to Idaho, and preparing an "after" package for Bobby, Dean, and Castiel. The "after" package was addressed to Bobby's scrapyard, and contained letters to Bobby, Dean, and Castiel, and would also contain anything of his they might find useful after he was dead. He left the box out on the table in the cabin, open so he could place in it what he needed to before any experiments. He'd already set up a message that, unless he deactivated it every day, would automatically send to the local post office ensuring someone would come pick up the box in the event that one of his experiments actually worked. He didn't pack everything up to start with because he still needed his laptop, and he'd taken to wearing the amulet now that he was on his own, and he wasn't going to put that in the box unless he was certain he would be successful.

The letters he had done as soon as he finished setting up the cabin. The one for Bobby was largely a thank you letter to the man for essentially being the best surrogate father they could have ever asked for. It was also full of Sam's gratitude that Bobby hadn't exiled him after he'd set Lucifer free, because God knew he'd needed the support. Dean's letter was considerably more detailed in the various facets of Sam's gratitude. After all, his brother had practically raised him, and Sam had idolized Dean for pretty much his whole life. There were a lot more apologies in Dean's letter too, because Sam kept thinking of other things he should express his regret over. Ultimately, if he somehow garnered Dean's forgiveness, that would be all he desired, and Sam let that be his guide as he wrote to his brother.

Castiel was a whole other story. Sam had waffled over writing the angel a letter at all, but decided in the end that he had to. While Castiel may have been closer to Dean, he had saved Sam's life multiple times, and had never rejected Sam, even though he was clearly aware of the fact that Sam was corrupt. It was hard for Sam to deal with the fact that the angels didn't want him, but at least Castiel didn't hate him, and that was huge. That ended up being the primary theme of Sam's letter to the angel, along with apologies that Sam felt were relevant and appropriate.

Once he'd gotten that emotionally draining process out of the way, Sam sat down with his laptop, took a deep breath, and started the mission he'd isolated himself to do. One way or another, he would destroy any chance Lucifer had of gaining his true vessel.

Dean had made it to the hunt he and Sam had originally been headed toward the afternoon following Sam's departure. Based on the research they'd done ahead of time, it looked like a single werewolf, so Dean was confident he could handle it. Unfortunately, a visit to the coroner revealed that the autopsy information had been inaccurate. The hearts weren't missing - they had melted into the victim's bodies. There was a cavity where their heart should be, but only because the muscle had literally liquefied. The kicker was that according to the coroner, all evidence of some kind of animal attack had been done after the victims were dead.

After doing what research he could by himself and coming up completely empty handed, Dean gave up and called Bobby the next morning.

"This better be good," Bobby warned him, forgoing a hello. "It's seven in the morning and I haven't had any damn coffee yet."

Dean snorted. "Me either, so I'll be quick. So, if I say to you supposed victims of an animal attack with missing hearts, you say...?"

"Werewolf," Bobby said immediately, as though the answer was obvious. "Which you know, so what's the problem?"

"According to the coroner, all evidence of animal attacks was after the vics were dead, and the hearts weren't taken, they melted. The heart is technically still in the body, just in liquid form." Dean announced the new findings with a tone that very clearly indicated he wanted to see exactly what Bobby made of that.

"Screw it, I'm getting the coffee now," Bobby muttered. "All right, so you've got a weird one. Any theories?"

"Why do you think I'm calling you?" Dean snorted. "I've exhausted what I can do with a library research computer. I'm stumped."

"What, Sam couldn't find anything on his laptop?" Bobby asked, miscellaneous banging noises in the background indicating he was making his coffee.

Dean winced. He hadn't wanted to have this conversation with Bobby so soon, but the hunt hadn't really left him a choice. "Sam's, uh, not here."

Bobby's background noises paused, and he asked carefully, "Then where is he?"

"Not sure," Dean admitted. "We decided it would be mutually beneficially to go our separate ways for awhile, so he took off night before last."

"Dammit, Dean!" Bobby snapped, a clink sounding like he'd just slammed down a mug. "I thought you idjits had already established that splitting up was a bad idea."

"Yeah, well, this time it was for the best," Dean argued defensively. "We weren't really helping each other by being together."

"Boy, last time you two split up, you got kidnapped and hurtled into the future by Zachariah, and Sam-" Bobby cut off mid sentence, then continued with, "You two are weaker apart, and always have been. People will come after you if they figure out you're flying solo."

Bobby was the only person Dean had gone into detail about his 2014 trip with, mostly because there was no way he was telling Sam or Castiel the details, and Bobby would be able to get his head in the right place, which he had. Dean was distracted by the unfinished sentence though. "Sam what, Bobby? Did something happen when we were apart before?" All Sam had ever told Dean about their time apart was that he had found a job and laid low in Oklahoma, trying to get his head together. Apparently Bobby knew more than he did.

"Nothing," Bobby said firmly. "It ain't my place, it's Sam's. God alone knows why you two idjits keep secrets from each other though. All my gray hair and the spots that are altogether bald? It's your fault, the both of you."

Dean half chuckled at that, not being able to remember a time when Bobby hadn't been gray and balding. "If something happened, I need to know about it," he tried to reason.

"No, what you need to do is track down your brother and work on this broken team dynamic you're apparently suffering from again." Bobby insisted.

Dean scowled, reminded of the disastrous trip to Heaven and the clear sign that to Sam, they were anything but a team. "It's a lot of things, Bobby, but we're going to tackle this thing separately, and work from different angles. Once the apocalypse is over, we'll work on it, okay? Look, do you have any ideas about the hunt?"

Clearly dissatisfied, but declining to argue further, Bobby sighed. "Nothing springs to mind, but I'll look into it on this end. Why don't you ask your guardian angel?"

It hadn't occurred to Dean to use Castiel as a resource the way he did Bobby, but he had to admit it wasn't a half bad idea. "If he answers his phone," Dean pointed out.

"Doesn't hurt to try. Let me know if you figure it out. Otherwise I'll call you if I find anything." Bobby took a sip of something on his end and sighed contentedly.

"Will do," Dean confirmed. He snapped the phone shut and stared at it for a second, before flipping it open again to dial Castiel.

"Yes, Dean?" The angel answered on the first ring.

"Woah, that was quick," Dean said, surprised. "Look, I'm in Opal Basin, Illinois, Tulip Grove Motel, Room 26, and I need-" Dean cut off mid sentence as Castiel appeared in front of him. Hanging up the phone, he tossed into onto the bed behind him and continued his sentence. "I've got a really weird case, and I could use some help."

Castiel eyed the room curiously, not responding immediately. He took notice of the single bed and the luggage for one person, then turned to Dean, expression curious. "Where is Sam?"

Dean frowned, irritated by the fact that Sam's absence had overshadowed his need for help on this case not once, but twice now. "Gone, we split up two days ago. Can we focus on the case?"

Castiel's eyes widened in alarm. "Why would you do that?" He demanded.

"Do we have to do this now?" Dean asked derisively. "I have four victims that I can't explain how they died, and there'll probably be more if I don't figure it out."

"Dean, the apocalypse with literally end billions of lives. Yes, we do have to do this now. I will help you with your case, but we need to find Sam." Castiel's expression was urgent.

"Why? Dude can look after himself just fine," Dean said, exasperated. "He doesn't need a babysitter. He's off the blood, as far as I can tell, and certainly as independent as ever."

"He does not need to be supervised, Dean," Castiel scolded him. "He needs to be supported. The weight he is standing under is more vast than I believe you realize."

"How so?" Dean challenged, crossing his arms.

"Sam has been withstanding the onslaught of Lucifer's advances on a nightly basis for months," Castiel informed him gravely. "He is remarkably silent about it. I am only aware because he inquired if there was anything he could do to block Lucifer's entrance. Unfortunately, I do not possess the power to alter his mind enough in my weakened state, and there is no spell that could provide lasting assistance without damaging his mind. He has not mentioned it since, but I know it has not stopped. Based on what little he told me, I believe Lucifer alternates between psychological warfare and physical torment, hoping one will deliver Sam to him. Your brother is strong beyond measure, Dean." Castiel stared at Dean evenly, deliberate in his words to convey exactly what Dean had been missing about his younger brother.

Dean blinked once, visibly surprised. "That can't be right," he argued, tone too shocked to be angry anymore. "Sam's loud when he has nightmares. He's always screamed or cried or something. I'm usually the one to wake him up so he can actually get some real sleep. If Lucifer was torturing his mind at night, I think it would have been pretty obvious."

Castiel continued to gaze at Dean, though his eyes narrowed. "It is my belief that Sam turned to human medicinal remedies to attempt to solve the problem. Perhaps that is why you do not hear him."

Dean was suddenly and abruptly aware of the few times he'd seen his brother taking pills when he'd thought Dean wasn't looking. Dean had taken a peek when Sam was in the shower once, not sure if he needed to be worried, and backed off when he realized it was sleep medication. Nothing too troubling, so Dean had let it go. Now, he wondered if Sam took the medication to keep himself quiet, rather than to help him sleep.

"As I said," Castiel commented with a raised eyebrow, "Sam is strong. He is not, however, invulnerable, and neither are you. You both need support."

"Sam doesn't want my support," Dean snapped. The nightmare thing was concerning, but it didn't exactly overshadow the Heaven debacle. "That was perfectly clear in Heaven."

Castiel immediately looked bewildered, which was an unsettling expression on him. "What do you mean?"

"All his memories were of times he ditched Dad and I," Dean explained. "Doesn't exactly fill me with confidence." Castiel looked like he wanted to protest the assertion, but Dean held up a hand to stop him. "Dude, just drop it. I have some kind of monster I can't identify to catch, and if you could help me figure out what I'm looking for, that would be great."

Castiel frowned, but slowly nodded, deciding not to argue further for the time being. Internally, he resolved to search for Sam Winchester. Nobody could fight a war alone, no matter what Dean may think. Someone needed to remind them both that they had support, but Dean was too stubborn to accept Castiel's advice on the matter. Sam, on the other hand, Castiel was sure he could help. He just needed to find him first.

"Sam, wake up."

Sam slowly rolled over in bed, the thin sheet on the cot in the cabin sliding off of him. It hadn't really been enough to cover him anyway. "Go away," he snarled, glaring daggers at the stunning vision of his dead girlfriend.

Jess pouted. "Don't be like that, Sam. It doesn't have to be one of those nights. I promise, I'm not the bad guy here."

Sam rolled onto his back and stared at the ceiling. "This is getting old. I'm not changing my mind, and eventually you're going to completely run out new ways to try and make me."

Jess morphed into Dean, and Sam fell off the cot in shock at the transformation.

"Sorry, Sammy, looks like I still have a few tricks up my sleeve," Dean chuckled.

That was new. Lucifer was never Dean. "NO." Sam said loudly and firmly, backing up against the wall.

"I haven't even asked the question yet," Dean protested.

"I meant this," Sam snapped, gesturing to his brother's body. "You've corrupted the memories I have of Jess, and decimated what good memories I had of my parents. You don't get to touch Dean."

Dean shrugged and lounged on the cot, completely relaxed. "From what I gather, the two of you have been chipping away at your relationship anyway. You betray him, keep secrets from him, and eventually it's too much and he kicks you out. Sound about right?"

At least Lucifer was speaking as if Dean was somewhere else, not himself. That helped Sam stay grounded. The words still hurt though. "Once I've fixed my mistake, I'll be able to make it up to him," Sam determined. "I'll do whatever I have to to end you."

Dean chuckled. "Good luck with that. You will say yes."

"You always say that, but I never do," Sam challenged. He blinked, and suddenly he was back on his cot, strapped down with leather and bare chested, despite the fact that he'd been in a t-shirt seconds before.

"We'll see," Dean said casually, twirling a razor sharp blade between his fingers. "Should I go for the knives today, Sammy?"

"Don't call me that," Sam spat. Only Dean got to call him that, and he hadn't in a long time. This wasn't Dean though, so it didn't count.

Ignoring him, Dean continued, "You seem to have a fascination with carving your skin with sharp objects, so I'm not sure this is effective." The blade vanished, only to be replaced by a red hot poker. "Do you feel the same about burning flesh?"

Sam kept his jaw tight and stared straight ahead, attempting to suppress his reactions as Lucifer pressed the poker to his abdomen. Eventually, as Lucifer finished burning the letter "L" into his flesh, Sam began to scream.