Disclaimer: I don't own Supernatural.

He started coming to Sam in dreams almost immediately after he found his new vessel, but Sam never told Dean.

It wore him down and he no longer seemed able to get a good night's rest, but Sam could still hunt and he didn't want the fact that Satan paid regular visits to him weighing on Dean.

Dean didn't need that. Combined with their mother's leaving, of her own free-will and not because of a demonic death, the British Men of Letters, and just knowing that Lucifer was walking around the earth and no longer in Hell, the burden of that knowledge would be too much.

So Sam kept quiet about his restless nights. He knew that Dean saw the dark smudges under his eyes and the features of his face growing gaunt, but he had a fresh pot of coffee made each morning and a plastic smile. Dean would want to address it later, sure, but he left good enough alone for now.

Sam leafed through the pages of another worn book, its spine barely keeping everything together in its battered state. He couldn't read the tiny script, and it wasn't due to them being fourteenth century English and having that slight unfamiliarity of a different age about them. His tired eyes couldn't focus long enough to understand what he was reading. They burned and felt dry, no matter how many times Sam pressed the heels of his hands against them or closed them to try and regain some moisture.

Dean would be happy. He was researching because their mother asked him to. Mary was on her way over since she stumbled across something unusual while working on tying up her loose ends and asked for some help from them.

Unfortunately, the unusual thing she found wasn't due to her missing over thirty years on Earth. It was unusual, even to Sam.

But she asked for help and it would be hours before she arrived at the bunker yet, so Sam was determined to have some information for her by then.

Not like he was sleeping when she called anyway. Not like Dean, who slept through his phone ringing.

Which Sam realized was because he left his phone in the library. Mary was worried about it, but believed Sam when he said that Dean was fine.

And yes, he was sure that Dean was fine. How did he know? He peeked in his brother's room and found him sprawled out and snoring. And yes, Dean didn't hate her. He might not agree with her decision, but they understand that she needed some time on her own to adjust.

And maybe that last part was a bit of a lie, but Sam understood her need to get away from it all. He understood what it was like to feel like a stranger among people he should know.

So he prepared for another family hunting trip and whatever tension the mood between Dean and Mary would bring, hoping that, at the very least, he wouldn't become a liability to his family from his lack of sleep.

It was his smile, Sam thought, that earned Lucifer his nickname of Serpent. The way his lips curled over his teeth and bared them.

"Sam," he greeted. "Good to see you. It's been so long."

"Get out of my head. Just let me sleep," Sam said. "In peace."

"Say 'yes'. You can have all the peace you want," he said.

He walked in circles around Sam, both of them trapped in a cylindrical room without windows or doors. It reminded Sam of Bobby's panic room. Vaguely.

It was missing the stench of whiskey and Old Spice.

"That's never gonna happen," Sam said.

Lucifer shook his head. "No, I think it will, Sam. I think that you're going to hit a new low, and you'll need me like I need you. We're going to strike a mutually beneficial deal, Sam."

"I would never let you in again."

"You were adamant the first time," he said. He took a chair, spun it, and sat with his forearms rested on the back of it. "So, so adamant. I even told you last time that you would say 'yes' within six months. In Detroit. And you did, didn't you?"

"That was different," Sam said.

"The circumstances might have been different, but I knew then that you would let me in. And I know now that you will again. Only this time, I think it will be within the week."

Sam sat up with a gasp, that drew the attention of both Dean and his mother towards him from the front seat of the Impala. Questions asked, but not spoken.

"I'm fine," Sam answered. "Just a run-of-the-mill nightmare."

He added a laugh at the end, but neither of them were fooled.

Dean didn't want to know, but needed to know.

Mary didn't need to know, but wanted to know.

Sam just wanted (and needed) a night of sleep without The Devil taking over his dreams.

Dean gave him the we're-talking-about-this-later look.

Mary gave him what he assumed was her you-know-you-can-talk-to-me look.

Sam pulled on another plastic smile and stared out the window. He noticed it the first time he came back from Hell, after the wall broke, but now the landscape was a prominent reminder of how dulled everything looked after his stint in The Cage.

He thought it'd all be brighter, but things only ever darkened in his life.

The hunt was easy. The creature rare, but killed with a traditional beheading.

They were on their way back to the motel in no time. Dean tried to find a place a little nicer than their usual lodging choices for Mary's sake, but there hadn't been much to pick from and Mary insisted that she would be fine. She was a hunter, too, and could handle a seedy, no-tell motel.

Sam heard their breathing even out as they fell asleep, but Sam stayed awake.

He watched the bright numbers of the digital clock on the nightstand change minute-after-minute, until his exhausted body couldn't take it anymore and pulled him into sleep.

"You or her, Sam?" he asked.

"What are you talking about?" Sam demanded.

Lucifer circled him, grinning. "You. Or. Her," he repeated. "For being so smart, you are really dumb."

"Her who?" Sam asked.

Lucifer's grin just widened. "I always take what I want, Sam. No matter what I have to do or how long I have to wait to get it, I will get what I want."

It was a deep sleep that he was left in after Lucifer vacated his dream, but something kept falling onto his forehead. He flinched every time, but couldn't figure out what exactly caused it. The sensation was oddly familiar, but kind of tickled, and roused him from his sleep (which he still desperately needed) into a lull between waking and dreaming.

And there was dripping.

Drip onto his forehead. Flinch away.

Drip.

Flinch.

Drip.

Flinch.

After the third time, he was more aware and swiped his fingertips over his forehead to see what the hell was dripping on him.

The warmth made his eyes shoot open, wide and afraid, already knowing what he would see in the moonlight.

Mary stared down at him with unseeing eyes, a red cut across her stomach leaking blood.

"No!" he yelled.

Dean woke up and went straight to action as Mary's body was engulfed in flames.

Sam figured he knew the drill by now, as Dean grabbed him and dragged him from the motel room. Dean knew that once someone was on the ceiling, they were beyond saving, but it didn't stop Sam from reaching up and trying to get Mary down.

And all he could see was Jessica, years ago, burning with her dead eyes set on him below.

"It's not your fault," Dean said.

They stood in the parking lot with the other motel customers, watching firemen try to control the fire.

"You don't get it, Dean," Sam said. "It was my fault."

"You or her?"

Him or Mary. That was the choice that Lucifer offered. He took Mary, but would trade her for Sam, if he asked.

And maybe it was more of a choice for Dean. Should Dean have him or her? His brother or his mother?

"Sam, don't be ridiculous. Yellow Eyes should be dead, why would we have a reason to suspect something like this would happen again? How could a demon even get in? We salted the door and windows."

It wasn't the work of a demon, but Sam didn't tell Dean that. Angels weren't stopped by salt lines, and Mary didn't have Enochian Sigils carved into her ribs to hide her from angels. She was more vulnerable than they originally thought, and Sam didn't realize it until too late.

Dean's hand on his shoulder kept him grounded, but Sam felt like poison. He was the reason people Dean loved kept dying.

Mary died over his crib, and again over his bed thirty-three years later.

John died because they were hit by a semi. Because Sam couldn't even get them to the hospital without getting in a car accident that should have killed Dean without demonic intervention.

Dean died to keep Sam alive. Sold his soul and went to Hell.

He really felt like Brother of the Year.

"Don't you want her back?" Sam asked. "We barely got any time with her."

"Of course, I want her back," Dean said, his voice thick with emotions he tried to keep hidden, "but I think we both know how deal making ends. She wasn't happy here. She's back with Dad."

"I can get her back for you, Dean," Sam said.

He wiped at his eyes and looked at Dean, removing the scorched motel from his sight.

"I think it will be within the week."

"Whatever you're thinking, Sam, it's a bad idea and the answer is 'no'," Dean said.

He looked more angry than sad, then. More worried than hurt.

"But she died because of me. Again!"

"I don't care," Dean snapped. "We kill what did it again. Let her rest in peace. We're out of favors, and we both know that what's dead is happier staying dead."

Sam was glad that they were off in the corner more. That anyone close enough to catch snippets of their conversation would probably write them off as unstable rather than pay too much mind to their ramblings about death and deals.

He wasn't convinced with Dean's solution. The simple we-kill-it approach. The reason that they were pulled into the hunting life in the first place.

They couldn't keep repeating their mistakes.

Sam still smelled burnt flesh.

Dean didn't need a brother like Sam, no matter how tightly he gripped his shoulder to try and push away Sam's unknown plan. Trying to push away Sam's guilt over something he didn't see as his fault.

"You or her?"

"I'm sorry, Dean," Sam croaked out. "I'm so sorry."

Dean wrapped him in a bone-crushing hug and kept telling him every variation of 'Not your fault, Sammy' that he could come up with.

Only Dean didn't know what, exactly, he was apologizing for.

Because Dean would never forgive him.

Author's Note: I have it in my head that they're going to off Mary by burning her over Sam's bed. Again. I doubt that the show will go that path, but hey, I'll write it out anyway with a bonus "Sam says 'yes' again" section.

Please leave a review, I'd appreciate it!