"This is it?"

Henry was looking at the building skeptically. The part which stood above ground was admittedly looking a little worse for wear, but that's what happened when no one was around to perform upkeep for half a century.

"This is it," Cass confirmed. "Do the honors?"

Slowly, he extracted the key from the box and unlocked the door. The door swung open to reveal backness, and Henry accepted a flashlight from Sam. Sinclair, with a roll of his eyes and a whispered word, conjured a gleaming ball of light and tossed it into the bunker, illuminating the surroundings as they descended the stairs single-file.

Dean whistled. "This place is huge."

"It was designed to house up to two dozen men indefinitely," said Sinclair. "If it had been staffed at the time of Abaddon's attack, the Men of Letters might have survived."

Sam nodded to a table which housed a chess board, ash tray, and a few coffee cups. "Looks like it was."

Henry looked at the abandoned chess game mournfully. "They must have responded to the distress call when Abaddon attacked."

A soft hum filled the air as the electric lights switched on. Stepping away from the switch box, Dean turned slowly to take in the whole room. "What all is down here?"

Cass looked at Sinclair for an answer, and found him looking at her for the same. He shook his head. "I only designed the warding. I never saw the final blueprints."

"I haven't seen the whole thing," Cass said, thinking over what she did remember off the top of her head. "I know there's living quarters, kitchen and showers, the library, a garage, store rooms, a small dungeon—"

"Just a small one?" Dean joked, eyebrows raised.

"And I think there's a room dedicated to some massive, antiquated computers, too," she finished. Taking in the eager expression on his face, she warned tiredly, "Try not to knock anything over while you explore. The Wicked Witch of the West is trapped in a jar or something in one of the store rooms, and I don't really feel like dealing with that today."

Dean stared at her blankly. Sam and Henry did, too. Hesitantly, Henry said, "That's not a joke, is it."

"Nope." Cass ran a hand through her curls and added, "Though we'll have to deal with it eventually, because Dorothy's in there, too."

Dean shook his head and turned to explore down the hallway. "Just when I think things can't get any weirder…"

Bobby joined Dean in his exploration of the bunker, while Henry and Sinclair began sorting through the library, looking for any books which might prove useful. Cass drifted down the hall, opening doors just long enough to find a bedroom.

She was exhausted—between the stress of being kidnapped, the chaos of being rescued, the stressful aftermath of questions, and then the jarring revelation that her treasured pet was actually some kind of heavenly entity, she felt like she'd been awake for days. She collapsed onto the musty sheets, closing her eyes with a groan and hoping Forrest would have the good sense to curl up somewhere else for a while. A few seconds later, she heard footsteps pause in the doorway.

Without opening her eyes, she sighed. "Hey, Sam."

"Hey." The door clicked shut, and a moment later the other side of the bed dipped. "Are you really okay?"

Cass blinked her eyes open and turned to look at him, taking in the concerned frown on his face. She was a little surprised—she'd been anticipating a lecture, or maybe even some shouting. The concern warmed her.

"Yeah, I'm fine." When Sam's worried look didn't dissipate she frowned. "Seriously, Sam, apart from grabbing my hand when we teleported, he didn't even touch me."

"Good," he said, relaxing a bit. "That's good." Then, at her curious look, he shifted and said, "With all the stuff about collecting people, I thought—I dunno…" He trailed off, but Cass thought she understood what he was saying.

"The creepiness was one hundred percent platonic, I assure you. Honestly, I'd be more worried about your grandfather than about me." She wasn't exactly complaining since it had gotten them all out of a sticky situation, but Sinclair's deference to Henry was almost alarming in its contrast to his typical behavior.

"Yeah," Sam said. "About that."

Here came the lecture. Hoping to head it off, Cass said, "I'm sorry I didn't tell you about him, or Adam. But there was nothing you and Dean could have done about them at the time, and we do have bigger things to worry about."

"That's what you say, but then something like this happens," Sam said. He seemed to be making an effort to contain his frustration. "It would've been nice to know what we were walking into here, Cass."

"I know," she said, averting her eyes. It hadn't occurred to her until afterwards just how infuriating it would be for Sam and Dean to walk into that situation blind. "I'm sorry."

Sam was quiet for a long moment. When Cass finally met his eyes again he said softly, "I think you need to tell us everything. The way you told Bobby."

Cass bit her lip. "I don't know, Sam…"

"That's exactly the problem. You don't know. What happens next time something changes? What other information are you sitting on that we need to know about?"

He was right. She knew he was right. Maybe it had been a good idea to withhold information at the beginning, but now? Now it was more of a risk than a benefit.

"We've put a lot of trust in you, Cass," Sam said earnestly. "You've gotta trust us back."

Cass let out a shaky sigh and nodded. "Okay." Sam smiled brightly and she hurried to add, "Just you and Dean, though, alright? Your grandfather is probably okay, but I don't trust Sinclair as far as I could throw him."

Sam took up her left hand in his uninjured one and squeezed it. "Thank you."

"Don't thank me yet." She squeezed his hand back. "Sam… you're not gonna like hearing a lot of what I have to tell you."

"Yeah, I figured," Sam admitted. "But you know I won't hold that against you, right?"

She didn't know that, but hearing him say it did help. With a sigh she whispered, "I just… there were some things I hoped I'd never have to tell you. I hoped I could just stop them from happening, and you'd never have to know."

Sam was quiet for a while. When he spoke next he kept his eyes on the ceiling, seeming to choose his words carefully. "I get that you're trying to protect us. But you're not alone, you know? Whatever's coming, even if it's bad, we'll deal with it together. Same team, remember?"

"Yeah." Cass sighed. "Yeah, okay."

She tugged her hand away and sat up before she could get used to the feeling of their fingers intertwined. For all that Sam had said he wouldn't hold what she told him against her, she doubted he'd want to hold her hand once he knew exactly how much she'd been keeping from him.

She cleared her throat and made an effort to sound business-like and unaffected. "When do you want to start? It took me a couple days to get through it all with Bobby, but we'll probably want to head back to his place first. If we stayed here we'd need to work out some way to keep Sinclair from eavesdropping, and I don't know if that's—"

"Cass." Sam clasped a hand on her shoulder, gently urging her to turn around.

"Feasible," she finished lamely. Sam's expression was one of fond exasperation, and she wasn't sure she liked it.

"There's one thing I want to know first," he said, watching her reaction carefully. "Now."

Cass frowned, glancing at the door. "Shouldn't we wait for Dean?"

Sam huffed a laugh. "Definitely not."

And then he was kissing her. Gently, at first, a question—until Cass kissed him back, wrapping an arm around his neck and pulling him closer. Sam hummed, snaking an arm around her waist, tangling the other in her hair as he deepened the kiss.

It was better than any day dream. Kissing Sam was like coming home, warm and peaceful and right, but it was also like catching fire because she burned hot where his hands touched her and all of a sudden there wasn't enough air.

"Stop," she rasped, hating herself even as she said it but knowing she'd only hate herself more if she didn't. Sam pulled away immediately, his pupils wide but his expression cautious. Cass unwound herself from him and pushed herself off the bed.

"I'm sorry, Sam, I can't—" She stopped, shaking her head because her words were coming out all wrong and she could tell by the look on his face that he thought this was a rejection when that was the last thing she wanted to do. "Not now. If you still want this after—after you've heard everything, then I'll be here. I promise I will be, Sam, but not… not until then." She swallowed hard. "Okay?"

Sam nodded, his expression soft. "Okay."

The silence was oppressive. Cass sat tensely, waiting.

Before, she had walked Bobby through everything she'd seen slowly, over the course of a few days. This was different. There was no waiting, no breaks. They began at dawn the day after returning to Bobby's place from Kansas, and then they didn't stop until past sundown.

It wasn't a pleasant experience. She'd done her best to stay calm and neutral as she talked, but it had been much easier to do that with Bobby. As much as Bobby may have been a key part of the story, he wasn't the main character. Sam and Dean were. And there was so, so much she'd never told them.

Dean had alternated between sitting taut as a bowstring and angry pacing. He shouted and ranted and asked both Cass and Bobby just what the hell they'd been thinking—and then, inevitably, he'd notice them both sitting patiently and waiting for him to be done because there was still more to tell, and he'd sink bank into the couch in resignation.

Sam's reaction was harder to read. Cass would almost have preferred for him to shout, too, because at least then she'd know what he was thinking. But he didn't. He frowned and looked distant and asked frequent clarifying questions, but if he was making any judgments about what he heard or Cass's decision to keep it from them, he didn't say anything.

Two things kept Cass going when she might otherwise have broken down under the stress. The first was that Bobby sat beside her receiving at least half of Dean's heated glares for being the person Cass had confided in first and collaborating with her in keeping secrets. The second was that Forrest had deposited himself in her lap at the beginning of the day and hadn't budged. The comfort she got from the warmth he radiated in her lap, from being able to keep her hands busy with stroking his fur when the agitation got too much, couldn't be overstated.

Not that it was an uncomplicated comfort—it was still tinged with the knowledge that Forrest was somehow the Hound of Heaven, whatever that was supposed to be. She had never heard of it before, and Castiel hadn't been able to shed much more light on it when she'd called him on the long drive back to Bobby's place. All he knew was that the Hound followed 'the chosen', and that it was supposed to be a reminder of God's will.

She didn't like it. Not only was it a complete unknown, she had no idea why it was with her. Castiel didn't know how the Hound was dispatched—it could have been sent by God, by Michael or Raphael, or even by itself. And there was no way to ask it because, for all that the Hound was heavenly in origin, it didn't speak Enochian or any other language. Her only consolation was that if one of the archangels had sent it, it was unlikely they could track her down with it, because if they could, they would have abducted her already.

So yes, the joy she received from Forrest's companionship was now somewhat diminished by worry and uncertainty, but she was still grateful for the comfort now that the story was told and she sat waiting for Sam and Dean to react.

At last, Dean stood abruptly. Instead of pacing the library this time, though, he headed for the front door, fishing his car keys out of his pocket.

"Dean?" Sam said cautiously.

"I'm going for a drive."

The door slammed. Cass winced. Sam, noticing, leaned forward to catch her attention. "He just needs some time."

Cass eyed Sam warily, because with that sort of sympathetic reassurance she couldn't help but think that Sam was taking this too well, and that made her nervous. Bobby seemed to have similar feelings because he said doubtfully, "And you don't?"

"It's… a lot," Sam admitted carefully. Directing his words to Cass he said, "I get why you didn't want to tell us a lot of it. But I'm glad you did."

Glad was not the word she'd been expecting. She frowned skeptically. "Really?"

Sam managed a half-smile. "Really."

She didn't know what to say to that. She yawned instead, feeling the emotional exhaustion of the last day catching up to her. "Sorry," she muttered, because if Sam was going to be so obnoxiously kind and understanding then the least she could do was stay awake while he thought things over and asked any other questions he came up with.

"Don't be." Sam's hand twitched like he was going to reach out to her, but he didn't. Cass noted the aborted movement with disappointment, but she wasn't surprised, either. When he spoke again she couldn't help but think his smile looked a little forced. "We've all been awake for nearly a day straight. Get some rest."

She was pretty sure that was code for Leave me alone right now. "Right." She averted her eyes. "Good idea."

And so she retreated upstairs with the Hound of Heaven on her heels.

Sam stared at the ceiling of the library without really seeing it.

He'd gone upstairs for a while, trying to sleep, but it was useless. His thoughts were too frantic, replaying everything he'd learned over and over in his mind. Eventually he gave up on sleep entirely and went downstairs to sit on the couch and nurse a beer while he waited for Dean to get back.

Sam would have liked to be angry. A part of him wished he could be like Dean, wished that his biggest problem would be the personal stuff that Cass had kept from them. At least that could be fixed with apologies and time and forgiveness—and it would be, because Dean's anger burned hot and he'd be pissed at Cass and Bobby for a few weeks, but they were still family and Dean would come around eventually.

Sam wished it could be that easy for him, but it wasn't. He wasn't angry—not like Dean, anyway. Because while all of Cass's secrets and omissions bothered him, it was what she'd been keeping secret that bothered him.

It didn't anger him. It horrified him.

All the things he'd done, all the mistakes he'd made… he'd known bits and pieces of it, vague allusions, but Cass had never gone into detail, clearly not wanting to talk about it. And now he knew why. The things he would have done, the path he would still be on if he hadn't screwed up a summoning ritual and pulled Cass into this dimension—it was like stuff out of a nightmare.

Taking up with Ruby, drinking demon blood, become so addicted to the power of it that he lied to his brother and killed Lilith, setting Lucifer free. The horrible things he did for the year when he didn't have a soul. Leaving Dean to rot in Purgatory, not even bothering to look for him. Being possessed by an angel who used his body to kill the Prophet who would have come after Chuck Shurley if not for Cass. Letting Dean become a demon, and then the ruthless measures Sam had taken to find him—actually convincing someone to sell their soul to a crossroads demon just so he could capture it and torture it for information.

And then there was the endless string of bodies he left behind.

The world would have been better off if he'd never even existed. He'd thought it before, but it was even more apparent now. Without Sam his mom would never have died. His dad and Dean would never have become hunters. Jess would still be alive, along with dozens of other innocent people. Dean would've had no reason to sell his soul and kick-start the Apocalypse, wouldn't have to worry about dragging Sam's ass out of the fire over and over again.

Cass would be home, safe.

Sam was selfishly grateful she was here, grateful for her stubborn determination to stop him from going down that dark path, but he couldn't help but wonder if it would be enough. Because even though he knew better now, even though he'd do everything in his power to make sure the future Cass had seen never happened, he was still the same person. He still had demon blood in him. He was still Lucifer's vessel. All that darkness and anger and self-righteousness that drove him to do all those horrible things, it was all still there. Maybe he wouldn't make the same mistakes, but that didn't mean everything was going to be okay.

Especially because, for all Cass's efforts, not that much had really changed. The first seal still broke. They hadn't managed to capture Lilith, and now it seemed likely that she wouldn't show herself again until it was too late and all the other seals were broken. Sure, Dean had gotten out earlier and Sam hadn't developed a taste for demon blood, but would that matter in the end if they couldn't stop Lucifer from rising?

Maybe something had been broken in him from the start. Maybe there was no changing some things. Maybe he'd be saying 'yes' to Lucifer after all.

Sam drained the lukewarm dregs of his beer when he heard the sound of the Impala pulling into Bobby's driveway. A glance at the clock showed it was a little after midnight when Dean walked in the door, looking calmer but still tense. Sam watched him cautiously.

"Hey. You okay?"

Dean didn't look surprised to find Sam waiting for him, though he didn't look exactly pleased, either. He ignored the question, walking to the kitchen to fetch his own beer and asking with a bite to his tone, "Where's your girlfriend?"

Sam, recognizing the distraction tactic for what it was, didn't take the bait. "Asleep. So's Bobby." Dean grunted, popping the top of his beer with force. "This isn't easy for her, either, you know. This stuff has been eating her up inside since she got here."

Dean snorted. "Yeah, I know. Bobby told me about that long, convoluted Lord of the Rings metaphor. I'm surprised you didn't get down on one knee right there."

"Dean."

"I don't know what you want me to say, Sam," he snapped. "You want to know if I'm okay? The answer's no. I'm not okay. I'm pissed. I'm pissed at Dad, and Heaven, and Hell, and Bobby and, yeah, I'm pissed at Cass, too. She shouldn't have kept all that stuff from us."

"I agree."

Dean scoffed. "Oh, really?"

"I do," Sam insisted. "Of course I do. You think I like being left in the dark any more than you do? I don't. I'm sick of lies. I'm sick of not knowing."

Dean pointed the neck of his beer bottle at him accusingly. "Then how come you're not pissed off, too?"

Sam sighed. "Because I get why she did it, Dean."

"Yeah, so do I," Dean said flatly. "'Cause she's a control freak, and she doesn't trust us. And she made Bobby not trust us, either, which is even worse."

"She was trying to protect us. They both were."

"Protect us?" Dean repeated, disbelieving. "By not telling us anything? How the hell is that supposed to protect us?"

"I don't know," Sam said, a sarcastic edge creeping into his voice now. "Maybe the same way Dad protected us by not telling us anything about Yellow Eyes? Or the way you didn't tell me that Dad said you might have to kill me? Or maybe like how you tried to hide the fact that you made a demon deal?"

"That is not the same thing," Dean said stubbornly, his voice dropping low in the way it often did right before the shouting started.

Sam ignored the warning sign and pressed, "How is it any different?"

"Because we're family!" It wasn't quite a shout, but Dean did pause, waiting to see if his volume had woken anyone upstairs. When he continued his voice was lower but just as fierce. "We're family. Those are our secrets to keep, not hers. This, all this, everything she knows, it's about us. She doesn't get to decide to withhold that from us, Sam, she doesn't have the right."

"Dean, we're all she has," Sam said, genuinely not understanding where Dean was coming from here. "She doesn't have a family—we're the closest thing she's got, and she's done nothing but try to protect us. And she didn't have to. I mean, you heard everything. If we thought our lives were dangerous before…" Sam shook his head. "If she was smart, she would have ditched us months ago, because even working under-the-table cash jobs with no documentation is safer than hanging around us. But she stayed. Even before she knew she was a Prophet, when she thought she might be kidnapped and tortured for information, she stayed. Dean, she rescued both of us from Hell."

"Yeah, okay, I get it," Dean said irritably, unmoved. "You still think the sun shines out of her ass. Excuse me if I don't. I've got a right to be angry."

"I'm not saying you don't," Sam sighed. "If you want to be angry, then fine. Be angry. But you should ask yourself if you're angry at her for what she did, or if you're just taking it out on her because you didn't like what she had to say."

Dean glared at him. "That's not what this is."

Sam raised his eyebrows. "You sure about that?"

"I'm sure."

Sam woke with a jolt, reaching for the knife under his pillow on instinct before realizing that the person who'd just barged into the room was Dean. The sky was still pink and purple, the sun not yet fully risen. It seemed too early for Dean to be carelessly shoving clothes into his duffel bag.

"What are you doing?" Sam's voice was still creaky with sleep.

Dean didn't look up from his packing. "I found us a hunt."

That woke him up. "Seriously? Now?" Now meaning after everything they'd learned yesterday. Going off for a drive was one thing, but leaving on a hunt so soon?

"Yes, now." Dean finally looked at him, his expression dead serious. "Listen here, Sammy. I'm pissed off, and I want to shoot something. Now, I'd prefer it if that something was a monster, but if you really want to stick around—"

"Okay, okay, fine," Sam said quickly. "Just—just give me a few minutes. Okay?"

"You've got ten and then I'm leaving without you."

Sam hurriedly got his own things together. It was a quick process, at least—they'd been on the road when Bobby called and had only been back for a day, so Sam had hardly unpacked in the first place. Which meant that he had a little over five minutes to say goodbye to Cass and reassure her that he wasn't leaving out of anger.

Bag over his shoulder, Sam knocked softly on her bedroom door. "Hey, Cass? You up?" He hoped she was. He didn't want to leave while she was asleep, without saying something.

The door opened quickly enough that Sam was pretty sure he hadn't woken her. She was still dressed for sleep, though, and he should have been used to how she looked in his old flannel shirt by now, but he wasn't. It still made his mouth go dry. Her curls were sticking up in every direction and she still looked a little tired and worn, but she was alert enough that she noticed the bag slung over Sam's shoulder immediately. She frowned.

"What's up?"

"Dean found a hunt," Sam said, watching as her eyebrows rose and then drew together, her lips twisting in something like resignation. "We're heading out in a few minutes."

He hesitated. There were a lot of things he wanted to say—I'm not angry. I don't want to go. And, at the forefront of his mind, I still want you. But he couldn't bring himself to say them. Couldn't bring himself to step forward and kiss her goodbye, even though he desperately wanted to.

Because really, she'd be better off without him. He was broken, and he broke everything he touched. Getting attached, allowing himself to become closer to her than he already was—it was bound to end in disaster. Better to say nothing. Better to have her think he was angry with her, if that's what it took to keep her safe.

He could see when Cass realized he wasn't going to say or do anything else. Her eyes widened, her lips forming a silent Oh. She swallowed, fixing her gaze at a spot somewhere over Sam's shoulder as she said, "Right. Well… good luck, then. Be safe."

It was almost enough to change his mind. But only almost.

"Yeah. You, too."