Nearly an hour later, Dean decides to drag Castiel upstairs. There's probably some kind of significance to the fact that Crowley hasn't returned, gloating, just yet. But Dean's too damn hungry to think straight, and his stomach has gone past growling and moved on to cramping.

The wall feels bumpy against his back as he slides down it and plops to the ground, too tired to find a more comfortable spot — not that there is one in this hole of a shack.

"Oh right," Castiel mutters when they get back to the devil trap decorated main room. He wanders out the front door with no preamble, and comes back in minutes later holding two white paper bags. "I got burgers. They're cold now." He drops one of the bags in Dean's lap.

Dean pulls out the burger from the bag and unwraps the crinkly yellow paper. It's greasy on the inside and the burger is indeed cool, but it smells awesome and he devours it in about four messy mouthfuls.

Castiel is holding up a pickle slice and sniffing at it suspiciously, when a chill runs through the air.

The floorboards creak from somewhere to the left of him, and Dean turns his head. There's a long shadow — cast by the dim light from the doorway between this room and the next. Dean's heart stops a half-beat before the owner of the shadow speaks. Because it knows who's standing in the other room, even before he does.

"Hello, Dean."

The floorboards creak again, as Sam's boots walk into the main room. Sam's shadow disappears into the darkness of the rest of the room, and Sam's eyes look down at Dean with a smirk that isn't a thing like Sam's.

Dean stays on the floor, and crumples his greasy wrapper into a ball. He tosses it into the air once, twice and catches it between his fingers. "So you got out, huh?"

"Mmm," says the Devil, as he steps over Dean's outstretched leg to stand in front of Castiel. "Hello, brother." He narrows his eyes and leans closer. "You're all hollowed out, aren't you? How sad."

"Yeah, well Purgatory ain't exactly Malibu, you know?" Dean says, pushing himself off the ground. He walks to stand next to Castiel and stares into his brother's eyes. He's in there somewhere.

"How did Sam free you?" Castiel asks, looking up at Lucifer curiously.

Sam's lips quirk into a lopsided smile. "I convinced him Dean was still in Purgatory. He was…very upset."

"How did that crack open the cage?" Dean asks. "What'd you trick him into thinking the cage was Purgatory too?"

Lucifer laughs. "I tried, but Sam could tell the difference." He taps one long finger against his temple. "Smart guy." He sighs contentedly and continues, "Sam cracked Purgatory open nice and wide. So wide, in fact, that it now feeds directly into Hell."

Castiel raises an eyebrow. "Right by the cage?"

"Bingo." The Devil straightens the torn collar of Castiel's filthy coat. "The souls from Purgatory were so excited about an exit, they didn't bother to check where it led. The influx was...massive. Earth-shaking, so to speak. Between that and two arch-angels straining against it, the cage just couldn't hold up. So, I slipped back into my Sunday best…" He rolls his head slowly to the left, preening. "…and here I am."

"And Sam?" Dean asks. He looks into his brothers eyes, searches for a trace of him, but comes up empty.

"He's asleep," Castiel says like it's a revelation. He looks at Lucifer in wonder. "And not because of you."

"Really, and how would you know?" Lucifer asks, his voice full of false mockery.

"Because I know the difference between subjugating a soul and occupying an unresistant vessel." Castiel nods. "You don't know what will happen when Sam wakes up."

"Sammy?" Dean asks, feeling a weak flicker of hope somewhere deep in his chest. "You in there?"

"Oh please," Lucifer scoffs, turning away from Dean.

"Where is Michael?" Castiel asks. "Did he not escape the cage as well?"

"Of course he did. He's in Heaven...what's left of it." He gives Castiel a bemused look. "I sent Adam up there with him, but he didn't like it there. He came right back down to Hell."

"Adam?" Dean said, his insides feeling heavy with guilt. "Why would he—"

"He's a Winchester, after all. Do you understand how long we tortured him?"

Dean's hand trembles as he curls his fingers into a fist. "Yeah."

"His soul isn't exactly human anymore. He's quite well-suited to Hell. He's probably studying with Meg right now."

"With Meg?" Castiel asks.

Lucifer laughs. "She mentioned that you've got quite the little crush on her. Yes, Meg was rewarded for her loyalty and given exclusive rights to torture Crowley for the next two centuries. She's having a blast." He turns to Dean. "She was Alistair's second-best student, Dean. Second only to you."

Dean ignores the Devil's taunts. "Sam? Now might be a really good time to wake up, okay?"

Castiel shakes his head and walks past Lucifer and Dean, towards the other room. There's sunlight starting to come in through the boarded-up windows, and little dust motes float in the air.

Dean shrugs. Trying to decipher why Cas decided to leave the room at that particular moment would just hurt his brain. He looks back at his brother's eyes, trying to look past the arrogant archangel. "Come on, man, you're stronger than him. You know you are."

Lucifer frowns. "You don't honestly believe that, do you?"

"He kicked your ass once. He can do it again." Dean says simply. He hears footsteps behind him and turns to see Castiel walking back in holding a knife and a plastic box.

Castiel opens the lid of the tupperware container revealing congealed red goop and dips the already blood-encrusted knife in it. "You need something he'll react to physically."

Sam's eyes widen as Lucifer looks down at the knife blade.

"Something his body needs." Castiel holds the knife tip up towards Sam's face and smiles a most unangelic smile.

Lucifer takes a step back with Sam's long legs, but Dean shifts just in time to hook his own leg around his brother's, bringing him down to the floor.

Sam hits the floor with a loud thump, and within seconds the knife is back near his nose, Castiel looking into Sam's eyes intently.

A drop from the blade rolls off the tip, and lands right above Sam's upper lip. A full-bodied shudder runs through him and his eyes flood solid black.

Dean pulls the knife away from Sam's face, nodding a silent thanks at Cas.

Sam lets out a pained moan when his tongue finds the drop of blood. He stares up at Dean and his eyes fall back into their usual hazel.

"Hey there," Dean says and his voice only chokes a tiny bit. "You back with us?"

"I'm—" Sam licks his lips. "I'm thirsty."

Dean nods, "I'll get you something." He heads over to the carton of bottled water he saw stashed in the corner and brings one back to Sam, twisting it open along the way.

Sam sees the bottle and looks like he's about to protest, but then he clenches his eyes shut and drinks, his hand shaking. He gives the bottle back to Dean. "I can feel him."

"You've suppressed him," Castiel says. "That's…very impressive. Especially given your condition."

The bitter laugh from Sam makes Dean's stomach do flip-flops and he eyes his brother warily, waiting for the other shoe to drop. "My condition. Funny thing, actually…" Sam says. "Something about the dragon hearts, the blood of Purgatory…I think— I think it changed me, Dean."

"Changed you how?"

"Back in Stull, it took everything I had to hold Lucifer back, and that was just for a few seconds. Just long enough to—" Sam sits up, shaking his head like he's fighting off the sense of vertigo from the memory. "But just now? You woke me up, and all it took was a little push. It was way too easy." He laughs and there's an edge of madness there. "Something's different."

"Lucifer is not any weaker, in fact he seems far stronger than before" Castiel says steadily. "And although your power is great — for you, you are not stronger than him. There's something else at work here."

Sam turns towards Dean and squints at the light coming in through the breaks in the wood. "What time is it?"

Dean shakes his head and glances down at his wrist. It's a reflex he hasn't been able to get rid of, even though he lost his watch months ago. A wendigo had ripped it off his wrist, which at the time had been a relief, since he still had his arm afterwards. "No clue. If I had to guess? Probably close to noon."

"We should go outside. Can we go outside?" Sam asks.

"Yeah, sure," Dean says, nodding. "I haven't seen the sun in…a while." He doesn't actually know how long they were gone, not that it really matters in the end. He's out, and he intends to stay out.

"The car is low on gas," Castiel announces as they near the door.

"I'll keep that in mind. Also, for the record — you're not driving again. That was a one-time thing." Dean says, wincing at the haphazard way the Impala is parked. It looks dirty, which he supposes is largely Sam's fault. He'd been busy tearing open Purgatory, and let the car maintenance fall by the wayside. He should be pissed, probably, but on the other hand — he's not in Purgatory anymore and Sam somehow booted the Devil out of his brain. He can wait another day before giving Sam shit about his baby.

Sam stares up at the sky, and a ghost of a smile passes across his face. "It feels good out here. It's quieter than Hell."

"And it doesn't stink, like Purgatory," Dean adds with a smirk. "That place made me wish I had a sewer-scented air-freshener, seriously."

The laugh Sam gives in response is a shadow of its former self, but it'll do for now. Things will get better. They will. Dean sits on the hood of the car, and waits for Sam to sit next to him. Castiel stands next to them, looking at the leaves of the trees blowing gently in the wind. They stay like that for a long time.

After a dinner of Chinese food and two beers each, they decide it's time to look for a place to sleep. They're not staying in this hole another night — they'd just come back here to eat so they could pick up Sam's duffel and his weapons-stash.

Sam's on his way to the Impala's trunk when he stops walking and doubles over in pain.

"Sammy?" Dean is at his brother's side in seconds.

"Something is happening," Castiel says, watching Sam.

"Genius observation, Cas." Dean helps Sam to the ground. "Sam, you okay?"

"It's opening. I can feel it." Sam groans in pain and grips at the soil with his hands.

"What's opening?" Dean doesn't know what to do, and he hates that more than just about anything.

Sam's eyes bleed black. "Purgatory."

"Purgatory? But I thought you like annexed it to Hell, or whatever."

"Is that—" Sam winces again, clutching at his chest. "Is that what he told you?"

Dean nods. "Was he lying?"

Sam shakes his head, "Not exactly. I did, but it's not that simple."

"Cross-dimensional geography is never simple, " Castiel says solemnly.

"Damnit, that's why it was so easy to push him aside. Because of Purgatory." Sam says, like it's a revelation. "I opened it when I was in Hell, but I'm the door." Sam says, and his eyes shift from black to some milky shade of green. It's the same shade as the water in Purgatory. "I can't— Dean, I can't hold on, I'm sorry." Sam's body starts to shake violently and then he falls completely still. Dean reaches for him, but his hand sinks into the soil instead. Sam's gone.

Wings beat from somewhere behind them and Dean turns around to see Lucifer looking down at him with Sam's eyes.

"What did you do to him?" Dean asks as he stands up.

"Me?" Lucifer's eyes widen. "I didn't do anything. Sam's soul is a bit preoccupied at the moment, that's all. His heart's currently acting as a portal between Hell and Purgatory. There's a lot of immigration and emigration going on. The paperwork's going to be a nightmare."

"His heart?" Dean glares at the Devil. "His heart was in his body, last time I checked."

"You are a smart one," Lucifer says, smirking. "His heart — metaphysically speaking. This might be a bit much to grasp, but I'll try to dumb it down for you."

Dean resists punching Lucifer, because he wants to hear the answer, and because he knows he'd just end up with a broken fist.

"Hell isn't just my kingdom, it's a part of me. It was made of me. Therefore, as long as I'm in Sam, Hell is inside of both of us. And now, thanks to Sam, so is Purgatory." He turns to wink at Castiel, "And you know what that's like, don't you, little brother?"

"Anyway, in really simple terms: Hell burns with the fire of the sun, so during the day, Hell — my kingdom, reigns, but at night, the time of darkness, Purgatory rises."

"So…during the day Sam's in charge, but at night he takes the backseat again?" Dean repeats incredulously.

"Got it in one." Lucifer reaches forward to pat Dean on the shoulder, but Dean steps back, just out of reach. "Don't worry. It's nothing your brother can't handle. He's very resilient."

Dean's stomach sours, thinking of Sam having to go through this every day. "So this is like…some kind of Jekyll and Hyde deal?"

Lucifer laughs, "More like Persephone, I think."

"The only one who calls my brother a chick is me, got it?" Dean says, humorlessly.

"Of course," Sam's lips curve into a smile. "I have to say, all things considered this arrangement isn't all that bad. While I don't appreciate being locked up in my vessel's mind for half the day, I do like the idea of seeing you more often."

Dean rolls his eyes. "I don't want to see you. I want to see my brother."

"Well in that case, I'll see you tomorrow." Lucifer winks, and with the sound of beating wings, he's gone.

Sam returns the next morning, and vanishes as soon as the sun begins to set. The same thing happens the next day and the next day and the day after that.

Dean wonders sometimes if he ever really left Purgatory, or if Purgatory just followed him home.