The blare of AC/DC in his headphones wasn't enough to drown the nightmares from Dean's mind. He sat in the dim light of his room, propped on the soft memory foam, his back against the wooden headboard. His fingers gripped a thin stack of grainy photographs—tight, but not tight enough to hazard a wrinkle. His glassy eyes stared at the images, but their shapes were but a blur, his mind racing rampantly a million miles away.

Not three weeks ago, Dean had been hunched over a body in an alley. He'd run into the man at a bar—Dean didn't know his name. He'd jabbed a finger in Dean's face, his spit splattering Dean's shirt as he spoke. When Dean had snapped back, the man suggested they take it outside. Dean agreed. He couldn't even remember what had set the man on his case—was it his bad karaoke? Was it some obnoxious disruption he'd caused? Was it how he hit on every woman who'd stepped through the door, was it the things that made their cheeks turn scarlet or earned him a sharp slap across the cheek? Had he stolen the guy's drink, hustled him in pool, insulted his masculinity? For the life of him, Dean couldn't remember what had sealed the man's fate. All he could remember was laughing as the man swung time and time again, and then laughing as he returned the favor, pummeling the man until his skull caved into the pavement. And he remembered getting up, brushing himself off, and walking back into the bar for another round, once he'd cleaned off the gore from his knuckles in the bathroom.

Dean squeezed his eyes shut, releasing a shaky breath. When he reopened them, he tried to focus on the photograph in his hands. It was a faded photo—one he used to keep in his wallet. For a long time, he'd been unable to look at it, not without the heavy reminder of what they'd lost. It was one of his oldest photos, of Mary, hugging Dean from behind, taken when he was only three. Since they lost her, their father hadn't taught them how to grieve, hadn't exactly demonstrated a healthy example. Their whole lives had been built upon exacting revenge for Mary's death. It took a long time before he managed to bear a steady gaze at her image, though it had gotten a little easier when they'd finally killed Yellow Eyes. He still missed her, of course, and he thought he always would, but over the years, the ache had dulled considerably. Though, frequently, he'd still wished she was here, alive, so she could tell them how proud she was, so she could squeeze them tight in an embrace, so she could just be here.

Right now, in a rare moment, he thought it might be better that she wasn't.

What would she think, if she saw her boys now? If she could see what Dean had done while the Mark branded his arm, when his eyes went black… She'd be horrified. What would she think of Sam, hooked on demon blood so desperately that he'd die without the poison? Of Dean enabling the addiction, supplying the blood, even if it was supposed to be a means to an end? She wouldn't recognize her sons. She'd probably either weep or resolve to kill the monsters they had become.

He gritted his teeth and shifted the photograph to the back of the stack, the drum line in his headphones blaring on indifferently.

When his eyes were black, he'd often stalk the streets at night, for there was only so much to do for a sleepless demon. On one such night, he'd encountered a young couple clumsily breaking into a liquor store. At first, he'd almost decided to join them—it sounded like a mildly entertaining way to pass the time. But, for no reason in particular—perhaps out of a childish dream to play Batman—he'd found himself ambushing the thieves upon their hasty exit from the store. He'd shattered the guy's kneecaps to make him wail like a baby and fractured the girl's arms so badly she'd passed out, because he thought it'd be funny. With two good arms and two good legs between them, he thought they'd make an amusing image. Assuming he'd done enough damage, and he was almost certain he had, she couldn't exactly push him in a wheelchair, and he wouldn't be reaching anything for her off the top shelf any time soon. He'd sprinted off with their stolen booze before the cops showed, chuckling at the thought. He didn't know if they'd survived—he'd intended them to, for the sake of the mental picture—but at the time, it didn't really matter.

Dean ground his jaw, trying to focus on the riff of the guitar. His gaze flicked over the photograph in his hands—one of himself, Sam, and Bobby. A ghost of a smile tugged at his lips. He missed Bobby, too. The old man would probably have a few choice words about some of their recent decisions—maybe he could've stepped in before everything went to hell. He had a knack for cutting past the drama, to tell it like it was, to screw Dean's head back on straight. Something Dean could probably use right now.

Dean's thumb rubbed the edge of the photo lightly. What would Bobby think of their plan? He'd expressed resistance to forcing Sam through a cold turkey detox in the past—over fears they might be killing him. Apparently, maybe Dean should've listened, then.

He dropped the stack of photographs in his lap, pressing the heels of his hands to the sides of his head. He still struggled to believe Sam had died in that room, where Dean had locked him inside. He released a shaky exhale, subduing the thought, and collected the photos back into a loose stack.

Maybe Bobby would agree with their plan. He definitely wouldn't like it, but given the alternatives, maybe he'd understand this was their best—their only—shot.

He coughed as he slid the photograph behind the others, then rubbed his free hand over his forehead, squeezing his eyes shut against the low throb accumulating there.

The darkness behind his eyelids offered little solace.

A couple months back, early in his demonic sabbatical, he'd run into a young hunter at a dive bar. He didn't know her—in fact, he'd only approached her to see if he could coax her into bed—but apparently, she'd recognized Dean Winchester, the renown hunter who'd saved the world. Unfortunately, she evidently hadn't yet heard that he'd died.

She'd reminded Dean of Jo—a memory that hurt, now, but at the time, merely served to tempt Dean further. He could tell by her furtive glances and her frequent grins that she admired him—though he couldn't quite distinguish whether it was romantic interest or mere hero worship. Regardless, he'd toyed with it—with her—then, baiting her to join him on a hunt, and letting her think it was her own idea. He led her to an abandoned warehouse that night, encouraging her to take the lead, to show him what she's got, as he'd put it. It was an easy hunt—a couple dumb vamps, he'd assured, silencing her hesitation with cocky taunts.

And when the dozen vampires descended upon her, Dean had watched from the shadows, his smirk beaming in the dark.

When it was over, Dean didn't even bother to finish the job. He'd vanished, savoring the taste of her screams as the vampires gorged themselves on her blood.

Dean felt like he might vomit, so he swung his legs to the side of his bed, curling over himself. His hands were shaking—bad. He distracted his fingers by wiping them over his face, finding his skin clammy with sweat.

It wasn't you. He tried to remind himself. Sam and Cas had promised it wasn't his fault, and maybe they were right, maybe they weren't. But it was still his body, still his hands, they were still his memories.

His gaze trailed down to the Mark on his arm—the arm he'd gladly gnaw off with his teeth if he thought it'd rid him of its curse. That thing was to blame for all this. Sam wouldn't be drinking demon blood daily just to stave off a brutal death, if it wasn't for the Mark. Dean wouldn't be feeding his baby brother that poison. The poison that killed him even while it kept him alive. Over a dozen dead hearts would still be beating, their loved ones spared the lament at such senseless death.

A sudden vibration along his thigh made Dean frown and open his eyes, peeling his headphones off. As soon as he did, the ring of his alarm filled the air, and he dug his phone from his pocket, glancing at the hour as he silenced the sound.

It was time.

Dean planted his feet on the cold concrete, the raw emotion bubbling inside his chest. Without warning, he snatched up his headphones and hurled them across the room—the plastic snapped and shattered against the harsh impact, rebounding to the floor. Regret instantly twinged his gut, but he brushed it off, managing to not send his phone chasing madly after it.

Releasing a thin exhale, Dean stretched to set the photographs on the nightstand, affording one final glance at the image that now crowned the stack.

Sammy, a tiny baby, only a few months old, wrapped tight in Dean's arms, when the elder Winchester was barely four himself. Sam was swaddled in white, his bright eyes gazing at his brother in utter trust. Little Dean smiled sweetly at the camera, glowing with pride and adoration, his posture somewhat rigid as his arms curled protectively around his little brother, clearly cautious of the baby's fragility.

Dean couldn't remember the exact moment this photograph was taken, but he did remember cradling his newborn baby brother in his arms, staring in wonder at the helpless infant, knowing he'd been entrusted with something infinitely precious. Knowing, even then, that he wanted nothing more than to give his baby brother everything, to keep him safe, to preserve that bright joy in his eyes, to share with him the life of love and family that was all Dean had known.

How innocent they both looked, back then. He wondered what a beautiful, happy life they could've had ahead, with parents who wanted only the best for them, a safe home to grow up slow, like kids should, and blissful ignorance of the things that lurked in the shadows.

But none of them had protected Sam, that night when he'd needed it most. The night that cast out the Winchesters from paradise. The night the soldiers of hell claimed Sam with their vile infection.

Dean gently rested the photographs on the nightstand, releasing them with hands still quivering, before he wiped his palm over his face, over the wet stains upon his cheeks.

After a few more seconds, as he swallowed down his emotion and sealed it back tight to secure his composure, he moved to the foot of his bed and opened the chest, removing a small cooler. With a hasty glance backwards—though he quickly recalled his door was closed—he parted the lid to reveal a singular flask waiting in a bed of sloshy ice and water.

He chewed the inside of his lip as he withdrew the flask, testing its weight in his palm. It wasn't even half full. There'd be barely enough for this dose. But Cas would be back soon. He'd be back with enough for a couple days. Even that much was more than Dean wanted in the Bunker. But it'd give Cas enough time to secure more. If it helped keep Sam safe… they had to.

He fit the flask into his back pocket, though his skin crawled just at its proximity, and he stepped into the hall.

The bunker's silence enveloped him, proving a stark contrast to the roar of his headphones. He halted outside Sam's door, rapping his knuckles against the wood before easing it open, "Sam?"

His eyes skated over the room. The bed was made neatly, the books organized on the shelf, the floor clean and devoid of scattered laundry and garbage, and the desk set in orderly parallel and perpendicular lines. Another stark contrast to Dean's room, but it was empty.

Dean frowned, drawing the door shut, and started back down the hall, following the familiar path toward the library. His scowl deepened even before he turned the corner, at the darkness cloaking the room. He flicked on a light and scanned the empty space. Sam's laptop waited, closed, atop the table, accompanied by several pages of scrawled notes. A few empty beers littered the tables, the shelves; several books were dispersed throughout the room haphazardly; a couple jars of ingredients for an incantation lingered on the table—a reminder of yet another failed attempt at removing the Mark.

Dean stalked through the library, his pace quickening with the building dread in his chest, "Sammy?" He called, voice undeniably edged in anger, in concern.

For a heartbeat, Dean's stomach plummeted. Then, an unmistakable voice replied distantly, "In here!"

Dean released a slow exhale, relief unspooling the tension in his shoulders as he followed the sound to the kitchen.

Sam had his back turned to the door, his finger guiding his eyes quickly across the words of the tome splayed on the counter before him. He gripped a mug in the other hand; the rich scent of coffee that flooded the room easily betrayed its contents. His head turned a degree, just barely enough to introduce Dean to his peripheral vision, then he glanced at his watch and nodded.

He was slow to turn around fully, leaning against the counter as he hazarded a glance into Dean's eyes. He cradled his coffee in both hands, his shoulders curled inward, his head low. He looked exhausted, eyes dark and sunken, skin pale in stiff contrast. His movements were slow, like his body ached against every inch. But, all in all, he looked better than the first couple days of… treatment, Dean thought. Maybe his amended schedule was working after all.

"How are you feeling?" Dean broke the silence quietly, guardedly.

Sam scratched the back of his neck—stalling, uneasy. "I'm, uh… I'm okay." Sam raised his shoulders weakly, as though uncertain in his answer—as though uncertain of a safe answer.

Dean bobbed his head a few times, watching his brother warily. He hated this. But it was better to get it over with quickly.

He pulled the flask from his pocket, extending it towards Sam and averting his gaze.

Still, in the corners of his vision, he saw Sam's hand reach towards it, then pause, and curl back.

Dean's brow furrowed, and his gaze snapped upward as he demanded, "What?"

Sam set the coffee mug on the counter behind him, moving towards the table across the kitchen, his head remaining bowed low. Dean tracked his movement closely, his grip on the flask tightening. Still wordless, Sam unzipped a familiar black case, unfolding it to reveal a row of syringes. Dean's eyes flicked back up. It was what Sam had used to cure Dean of his demonhood.

"Sam?" Dean prodded in demand of explanation, following Sam to the table. He couldn't help but wonder if Sam had lost his mind.

"I, um…" Sam started nervously, planting his hands on the table to steady himself. He forced his gaze up to meet Dean's. "I think it might be better if we try it this way."

Dean stared at him, "You… you want… what?"

Sam swallowed hard, shifting his weight between his feet, "I think the… results would be more consistent. It should help with the measurements, too." He dropped Dean's gaze after a moment, "And, uh… Dean, it'd… it'd help with the… taste." He finished in barely a whisper, hazarding a glance upward.

Dean squinted at his brother, his skepticism a dark cloud, "You want to shoot up demon blood?" Sam retreated a step at the barbed question, wrapping his arms over his chest. "Is that even… safe?" Dean instantly felt like a fool for the query—of course it wasn't safe, nothing involving the blood was—but Sam could deduce his meaning.

"Yeah, I've… done it before." Sam rubbed his arm, controlling his gaze to the syringes, "When, uh… when Ruby was trying to get me to use my powers, I… resisted drinking the blood. She thought it might be a problem with the taste or the consistency or something, so she convinced me to try it this way." Sam offered a weak, halfhearted, self-deprecating smile, "It was never a problem with the drinking it, though, I just…" He shook his head slowly, "After a while, it, uh… it was just more convenient to drink it anyway."

At the mention of Ruby, Dean's body had tensed, and his mood soured considerably. He figured Sam had only risked the vocalization of her name in the pursuit of transparency. Even still, he wasn't sure Sam made the right call.

"I think it might help, Dean," Sam added—pleaded? "I think it might make it more… more manageable."

Dean was silent, studying his brother. He didn't like the sudden change, the sudden bizarre request in a procedure he already hated. He searched Sam's eyes, as though he might uncover his brother's motives for the proposition hidden inside.

Why would he ask for this? Did it make the demon blood more potent, make it act quicker? Was he trying to navigate loopholes in the slow detoxification, so he could feel the high a little stronger, ride it a little longer?

Dean spoke slowly, his voice still colored in disbelief, "You're telling me you want to inject demon blood into your veins… because you don't like the taste?"

Sam shook his head immediately, shame prickling his skin visibly. "No—Dean, it's… it's not that."

The lines in Dean's face thinned in realization. He wasn't asking for an injection because he didn't like the taste—he wanted it because he did.

Dean's gaze dropped as his mind buzzed. The slow detoxification was focused almost exclusively on easing Sam's body from its crippling dependence on the blood. But he also had to deal with the psychological craving—a factor Dean had pushed off and ignored, possibly taking for granted that Sam had managed to resist it before. But if Sam still wanted the blood, even when they finally got him off it, how could Dean possibly trust him to stay clean?

Sam's expression seemed to sink from Dean's hesitation, and he bit his lip, "Sorry. It's fine. I, uh… I shouldn't have said anything."

Dean's eyes scrutinized Sam, gaze flicking to the syringes. He paused, working his jaw as he weighed his next words. Finally, he spoke, "Wouldn't it be… stronger, that way?"

"To be honest, I dunno, but we could reduce the dosage, just in case," Sam explained readily, clearly having considered it. He raised his shoulders weakly, "I was thinking a fifty percent reduction to start… see what that does. The uh… the blood kicks in pretty quick anyway, so I'm not sure how much of a difference it'll make, though. We'll… probably need to adjust it, after."

Dean's hands clenched tight. He hated the uncertainty of the statement—the uncertainty of it all. He hated that Sam was the one calculating his own dosage schedule, but who else could he ask? He couldn't exactly google demon blood detoxification for suggestions. Frankly, he knew Sam was just guessing too—he'd admitted as much. The younger Winchester was merely the only one with any foundation to formulate his estimates. Still, Dean didn't like the idea of an addict determining his own drug intake in recovery.

Dean met Sam's gaze, and held it, "If you honestly think it'll help… you can give it a shot."

Sam's body relaxed visibly at the verdict, and he murmured, "Thank you."

The gratitude in his voice, his posture, bothered Dean. How much of a difference did it really make?

The younger Winchester sat at the table and prepared a syringe, then offered it towards Dean, the motion tentative. Dean removed the flask from his pocket, unscrewed the cap, and tilted it to fill the syringe with the dark, viscous fluid. The action felt surreal, like he was caught in a nightmare. A part of him wished he was.

He sat across from Sam, and, after squeezing the air bubbles from the syringe into the flask, he raised it, waiting. Sam proffered his elbow, his eyes tracking the blood. Dean lowered the syringe towards Sam's skin, but though his arms were steadied on the table, his hand kept trembling, the needle quivering in his grip. He stared at his shaky hands, willing them to still, his gaze flicking to the dark blood beading at the tip of the needle.

Sam's hand grasped his, gently. Dean's eyes slid upward, to Sam's face, which was touched in a blend of concern and sorrow. His fingers relieved the syringe from Dean's grip, his movements slow, allowing Dean to intervene, if he wanted to. When Dean merely watched, Sam leveled the needle against a vein—a practiced motion, one he'd done plenty in the attempt to cure Crowley and close the gates of hell. Only this time, he wasn't drawing out purified blood—he was injecting unholy, infernal poison. He released a slow, measured breath, before he pricked the needle through the skin.

Dean turned away almost immediately, a scowl twisting his face, but in the corners of his vision, he knew Sam didn't.

He forced himself a few glances back, obligated to monitor as Sam slowly plunged the dark blood into his vein. His breaths deepened and steadied beneath its cold caress, and the edges of his face relaxed ever-so-slightly. Either the pacing and gradual decline of the doses was successfully reducing the immediate rush, or Sam was getting better at hiding his relief.

As he drained the last of it into his bloodstream, Sam withdrew the needle carefully, his movements methodical as he set it on the table. He rubbed his elbow, his arm, as though to dispel the sting of the needle, or perhaps to motivate the blood's reach.

"You okay?" Dean finally managed to ask, his voice rough.

Sam locked eyes with him for a moment, then nodded as he looked away, "Fine."

It wasn't as… comprehensive of an analysis as Dean would've preferred, but it didn't surprise him, either.

Sam zipped the case of syringes closed, sliding it to the other end of the table. His eyes flicked back over Dean's hands—still shaky—as they sealed the flask and stowed it away.

"How about you?" He returned, lifting his chin slightly towards Dean's hands, as though to highlight the spark of his concern.

"What?" Dean frowned, his voice clipped and irritated, in the hopes Sam would back down. A few minutes ago, there was a good chance he might've.

"The Mark," Sam insisted slowly, quietly, "How are you holding up?"

"I'm fine," Dean dismissed, not bothering to withhold the biting irony from his tone.

"I've heard you coughing," Sam continued carefully, his voice low, "You're shaky. You look awful." Sam chuckled mirthlessly beneath his breath, "You look about how I feel."

"It's just a cold," Dean replied tightly, but the lie was cheap. Sam didn't even merit it with acknowledgement.

"You're getting worse."

Subconsciously, Dean gripped his forearm, the Mark aching under its mention. "One thing at a time, Sam."

"We don't have that luxury." Sam replied carefully, "As much as I know you want us to stay in lock down until I'm clean… Dean, we can't afford to."

Dean gritted his teeth, "You've only got another week or so left. We can wait till then."

"And when I get clean, then what? How long are you going to keep me locked up in here, afterward—till you trust me again?" His voice was deep, harsh, his words quick. Dean scowled at him in disturbed surprise, his own anger bubbling up from within his gut.

Before he could issue a retort, Sam dropped his gaze, catching himself almost immediately, "Sorry… I'm sorry, I didn't mean that." Dean held his tongue, and Sam pressed the heels of his palms to his eyes, "Cabin fever, or something."

Or something.

Dean watched as Sam took a deep breath, seemingly trying to collect himself, "It's just… we both know what the Mark needs. And you've been in here, with me, for the past week and a half, and I don't know how long it was before that."

Not long enough. But… too long.

"I know," he spoke quietly. Because Sam was right, as much as Dean wanted to deny it. It was something even whiskey couldn't drown away. No, that could only mute the tang of blood in his throat when he started hacking up his organs.

The Mark demanded violence. It demanded death. And if he didn't satiate its hunger, it was only a matter of time before it would exact its toll from his own body.

"I know you're trying to keep me safe, to help me get clean, and I'm grateful for that—I am. But if we keep ignoring the Mark… this'll all be for nothing."

Dean's gaze flicked between Sam's eyes. If Dean died and awoke a demon, again, he meant. But Dean wasn't sure if his brother was implying that Dean would overpower Sam and imprison him in another relapse, or that Sam merely couldn't complete his recovery without Dean at his side.

"Alright," Dean finally conceded, voice still taut, "I'll… switch out with Cas, find the next demon or two." Luckily, the Mark didn't discriminate. Killing a demon, a human, a monster—it was all the same. He probably should've done it before, but… he didn't completely trust Sam alone with Cas. He didn't think Sam would, necessarily, but… if Dean couldn't find a demon fast enough, and Sam's hunger drove him to desperate irrationality… it wasn't hard to shake an angel. All it took was a little blood and a hasty Enochian banishing symbol. Dean had escaped his own lock-down with it a few times. It wasn't that he expected Sam to do such a thing, because he knew Sam—or a part of him, at least—truly wanted to get clean. But Dean hated the thought of returning to the bunker and finding it empty.

When he glanced back up at his brother, Dean was expecting to find a satisfied nod in reply. But Sam only breathed a heavy exhale.

"What?" he snapped, irritation prickling his skin at Sam's apparent lingering discontent.

Sam was slow to reply. "I don't think you should go alone, Dean."

"What's that supposed to mean?"

"I just mean… you're sick too."

Dean scoffed, rolling his eyes, "Yeah, well, I'm not gonna run off to get a hit of demon blood."

Sam winced, but he recovered quickly, leveling his gaze, "No, but given the direction you're going, if someone looks at you the wrong way, you might just kill them."

Dean shook his head in disbelief at the blatant overstatement. He was fine. Sam was probably projecting his addiction, more than anything.

"Look, I'm not trying to pick a fight. I just… I don't think you should go alone, Dean." He searched Dean's face, adding somewhat desperately when Dean didn't speak, "What happens if you fall off the grid again? What am I supposed to do?"

Dean ground his teeth. "That won't happen."

"We can't know that," Sam held Dean's gaze, "Finding a demon isn't a milk run anymore. There haven't been any demonic omens within five hundred miles of here for the past week. Cas has had trouble tracking any down." His voice was resolute, but rimmed in concern, "You go alone, you could be out there searching for days. Even ignoring the fact that you won't let Cas bring back enough blood for more than a few doses, you really think that's gonna go well?"

Frustration gnawed at Dean's chest. The lack of nearby demons had been a growing problem—one he hadn't wanted Castiel to share with Sam. Apparently, he hadn't been clear enough. The angel had even suggested calling Crowley to give up one of his disfavored pawns, with some excuse about an attempted cure for the Mark, but Dean refused to consider it. He couldn't risk word getting out about Sam's relapse. Castiel promised he'd been careful—that not a single demon had escaped alive. It had to stay that way. No one else could know.

Dean shook his head, "So, what, you want to go with me? You really think I'm gonna let you anywhere near a demon?"

Sam exhaled through his nose, "Not a demon. Just a hunt."

"…you want to hunt? In your state?"

Sam's expression shaded in irritation, "I'm fine, Dean. I can handle a few monsters." At Dean's visible skepticism, Sam sighed, "Look. The safest thing we can do right now is stick together. You can keep an eye on me the whole time. You keep me in line; I keep you in line."

"Let me guess, you've already found a hunt?" Dean played off the question in a patronizing tone, but his gaze lingered closely on Sam.

Sam paused, and Dean wondered if he'd caught Dean's attentive scrutiny, before he answered slowly, "There's a vampire nest a few hours away. Should be enough there to… satisfy the Mark."

Dean went still at the mention of vampires. It couldn't possibly be the same nest—surely someone would've cleaned it out by now. He shoved the thought aside, focusing on his brother.

He hadn't caught it at first, but… why was Sam so set on leaving? Sam had already researched this—it wasn't a spontaneous ask. Was it really just cabin fever? Was it his addiction, masked in rationality, eager for an opportunity to score another hit?

Dean leveled his tone and prompted the question, watching his brother, "Why do you want to leave so bad? Really."

Sam bit his lip, then spoke quietly, "I found a lead, and I want to check it out."

"A lead?" Dean's brow furrowed, "You mean on the Mark?"

Sam nodded, "Yeah. There's this… book… and I've tracked it down to an old man that used to live in the area. It's ancient—like seven hundred years old, ancient—and… incredibly powerful, supposedly. If anything would have something about the Mark…" he trailed off, shaking his head, "Even if it doesn't, it's probably better we don't leave something like that out there, for someone else to find." He breathed a sigh, "I think it's worth a shot, Dean."

Dean rubbed his hands over his face, trying to quell the immediate doubt that clouded his reaction. As if they'd find the answer in some random book. Still… he wasn't sure where else he'd expect to find it. Though, maybe that was just it—he didn't.

"Sam…"

"I'm losing my mind in here, Dean." Sam added in a plea, his eyes and tone betraying his desperation, "I need to do something. And this could be it—this could have the cure."

Dean was silent for a long moment. He hated this. He hated not being able to trust his brother. He hated not being able to trust himself. He couldn't wait till this was all behind them… if it ever would be.

Maybe… maybe keeping Sam close wouldn't be a bad thing. It'd ease his worry about Sam giving Cas the slip. Dean would be watching him like a hawk—and he'd know it. A hunt, this lead—it'd keep Sam's mind occupied, too. Probably wouldn't hurt to keep him busy. And… maybe Sam was right. Maybe Dean could use someone keeping an eye on him, too.

"Fine. We'll wait 'till Cas gets back, then we'll go. But Sammy… you do as I say, and you don't leave my sight."

Sam nodded, meeting his brother's gaze, "Deal."