Sammy let me go, the note had said.

Castiel hadn't been sure what to make of the news. On the one hand, it meant that Dean wasn't dead. The crushing disbelief and sadness that had gripped when Metatron had relayed the news didn't apply anymore. Or did they? Dean wasn't dead, but he had been, and Cas hadn't been there to save him. And now he was alive, but he was gone.

"I'm coming," he'd told Sam. Sam hadn't asked him to come, but then, Cas hadn't expected him to. Sam hadn't asked him to come after Dean had died either. He'd wondered often (as pointless as he knew it to be) how long it would have taken Sam to tell him if Metatron hadn't. He wasn't sure what he'd done to lose Sam's confidence, but it was clear that he had. Sam hadn't even asked him to attempt to raise Dean, as he had five years before—not that, given the Mark's influence, that likely would have been successful. Whatever the reason, it seemed clear that now that Dean was gone, Sam had no more use for him.

He left Heaven without much fanfare and traveled to the bunker as quickly as he could. Unfortunately, car travel was infuriatingly slow. He gripped the Continental's steering wheel harder at each red light, each slow-moving minivan that blocked his way, each spot of city traffic that clogged up the highway as he passed by, and wished like he hadn't in months that he had his wings again.

It was silly, he knew. Even if he could fly to Kansas, he couldn't bring Dean back.

He knew the lore surrounding the Mark, knew what might have happened if someone had gotten the First Blade to Dean. Sam said that he had summoned Crowley to the bunker, and that with that invitation past the bunker's defenses, Crowley could have done just that. But Cas didn't say anything. They didn't know for sure, and in any case, he had his own doubts. What demon, after all, would leave a note? What demon wouldn't take the first opportunity to put an end to the person who Dean had sacrificed so much of his life for, as a first gesture of freedom? Cas couldn't bring himself to entertain the possibility that Dean was so good that even as a demon, he resisted doing the evil thing. No, it was far more likely that some other force had raised Dean.

He pulled up to the bunker eighteen long hours later. Frustratingly, he was already tired. It was like being human again, slave to the limitations of his vessel. He only hoped that his borrowed grace would hold out long enough for him to find Dean and bring him back.

Sam met him at the door, giving him a watery little smile and clapping him on the shoulder.

"Thanks for coming," Sam said.

"Of course," Cas said. "Has there been any word?"

Sam shook his head. "Nothing."

Cas fought down an automatic wave of disappointment.

Sam looked at him a few seconds, before shaking himself and saying, "Come on in. I've been contacting other hunters, putting feelers out, I've tried summoning Crowley like ten more times, I've been digging through the old Men of Letters stuff to see if they've got any heavy-duty locating spells. The normal ones aren't doing it."

Cas nodded. There were too many emotions swirling in him, emotions he'd never experienced until he'd fallen for the Winchesters—for Dean—for him to formulate a proper response. When Metatron had told him that Dean was dead it had been as if someone had reached into his chest and torn out any hope for happiness he'd ever head. Though he knew, now, that his friend was alive, that feeling still reverberated through him as a sense of loss that he hardly understood. On top of that were layered many others—anger at Metatron for causing all of this, fear for Dean, wherever he was now, impatience because after eighteen agonizing hours Dean was still gone and Sam had done everything he'd have thought of to do. He didn't want to spend his time digging through the Men of Letters' lore. Dean was gone, and if they couldn't find him, Cas might never see him again. He supposed he could go back to Heaven and seek answers there, but that would be another day's drive to return to the portal and in truth, he didn't want to be alone. And on top of all that, he was exhausted, stumbling over nothing as he followed Sam down the bunker's long corridors to the map room.

"At least he's alive," Sam was saying. "We know that much. We just have to find him. So that's, that's good. I just don't know how much more there is to do tonight. I mean, I might keep reading, but I don't know what you want to do."

"I want to help, Sam," Cas said earnestly. Physical exhaustion meant nothing compared to finding Dean and bringing him back.

"Yeah. I know, Cas," Sam said, considering him with his brows pulled together. "Maybe you could put some of that angel power to use, huh? Actually, I think there's a spell that that could use some extra energy. Here, check this out." He pulled a book from a pile on the table and flipped it open to a bookmarked page, then handed it to Cas.

Cas skimmed the text, one eyebrow going up as he did so. The text described a spell to enter the veil and communicate with its spirits en masse. The spellcaster would come out of it knowing whatever there was to know. The downside, the text noted, was that it took an immense amount of power to open a stable portal through which the spellcaster would return. Also, the author said, it often happened that the spirits would not be pleased with the presence of interlopers, and might try to destroy them.

"I'd go in," Sam said in explanation. "I'd just need you to stay out here and keep the portal open."

Cas set the book down. "This could be dangerous. For both of us."

"Well, yeah," Sam shrugged. "But it might help find Dean. If, you know, any of the bajillion spirits in the whole world have seen or heard anything?"

"Of course," Cas said, suppressing a sigh. He was tired, but he could find the power to supplement a simple spell. Sam had to be exhausted too, after all, and he wasn't giving up yet for the night. In any case, Sam was right. There was a chance it would at least give them a lead, particularly if Dean had passed through the veil at any point after being brought to life. "Do you have the necessary ingredients?"

"Yeah. I think so," Sam said.

They set up the spell on the floor in the map room. It involved drawing a complex, wiggly sigil on the floor in blood, which Sam provided without complaint, as well as the burning and placement of a few rare herbs and other occult ingredients. Sam would sit in the middle of the sigil, and once the incantation was read the portal would open around him, as if shooting up from the floor. Cas, for his part, was to remain on the outside of it, feeding power through the sigil through while Sam communicated with the dead in the other realm.

Sam took a seat in the middle, crossing his long legs and resting his hands on his knees, as if in a position to meditate. Cas stood beside him, just outside of the boundary of the sigil painted on the floor. He looked to the appropriate page, cleared his throat, and began the chant.

As soon as he finished the words (Sam watching him expectantly) there was a whooshing noise and a pale, ghostly energy shot up from the floor around Sam, encasing him in a cylinder of shimmering white. Sam's face went immediately slack, his eyes closing. The energy wavered but a second later, Cas had thrust his hand into it—gasping slightly because it was icy cold—and started feeding his own grace into it. Before long, the portal itself was tugging the energy out of him, siphoning it inward.

They'd planned to give Sam fifteen minutes in the spirit realm, and Cas waited as patiently as he could. At first, the energy that the portal had drawn out of him had been the easily accessible stuff near the surface, but as the minutes dragged on it was pulling intense amounts of power—far more than he'd expected—and was beginning to draw on the grace that was more deeply ingrained in him. With that came the unpleasant sensation of something scraping along inside as it flowed out of him, like sandpaper. He could feel his knees beginning to shake, as an absurd physical exhaustion overcame him. Five minutes… he could hold on for ten more.

Sam's face remained still, almost deathly still. Cas watched him, willing himself to ignore the growing pain of the grace being pulled out of him. (The sensation was almost like it had been when Metatron had taken it a year before. He decided not to dwell on it.) What had felt like sandpaper being dragged through him rapidly became barbed wire, then knives, then something indescribable. His knees gave out and he sunk to the floor, one hand still emerged in the pale energy surrounding Sam. Ten minutes. He had to do this. He had to do it for Dean.

It was then he noticed that the deathlike stillness of Sam's face had shifted to something else, his cheeks hollowing out, blackened eyes sinking back into his skull, his long hair thinning out as the flesh of his face stretched. The visage was that of a cadaver, and before Cas's eyes it was rotting away in fast motion. Whatever was happening, it was draining the life out of Sam, if it hadn't killed him already.

Cas pushed himself up, panic overriding even the agony flowing through him as the portal drank more and more of his grace. He couldn't simply pull away, for if the portal collapsed Sam would be lost forever (if he wasn't already) and Cas nearly panicked, frozen at the thought of losing Sam too, tonight. But it only lasted a moment before he had stumbled to his feet, his options considered.

He thrust his who body through the light, into the shocking cold. As soon as he did it was like being underwater and like being torn in a thousand directions at once as the grace drained out of him faster, faster, faster. He thought he heard the echo of voices, laughing and screaming from a greater distance, and had to fight to keep from being pulled in altogether. But with what little grace he had left could still feel the floor beneath his feet, his connection to the earthly plane, so he grabbed Sam—now a half-rotted away skeleton grinning at him where the flesh no longer covered his teeth—hauled him up, and forced himself out of the other side of the portal.

As soon as he was no longer touching it, the portal zapped out of existence, and Cas hit the floor on the other side with Sam in his arms. For a horrifying moment he couldn't see Sam's face, and couldn't tell if the rapid deterioration he'd seen had been a mirage of the ghostly plane or whether Sam's life force had truly been drained away. Then Sam rolled off him and started coughing, his very much alive face coming into view.

Cas could have melted in relief, had the knives-and-barbed wire sensation of his grace being dragged out of him not been lingering, along with a pounding headache and a bone-deep exhaustion the likes of which he could not remember feeling before. He let his head drop to the floor with a thud.

"Holy shit," Sam breathed, pushing himself up to his elbows and knees, and peering at Cas through the long hair falling around his thankfully flesh-covered face. "Cas. Hey. Are you okay?"

Cas couldn't quite find the strength to move from his current position, but he said, "Yes, Sam. Are you…?" A wave of horror flooded through him, as the image of what Sam had nearly become floated past his mental eye again.

"I'm fine," Sam said shakily, sounding surprised to find that that was actually the case. "Wherever I was, Cas, they didn't want to help me. They just…laughed. And kept trying to pull me to them."

He made it to his knees then started to help Cas into a sitting position. Cas gritted his teeth as the pounding in his head reached a new level, and the pain in his limbs burned as if real torn flesh were being moved. His vision swam. "I think they would have killed you," Cas said, as Sam rested him back against the nearest wall. "You appeared to me as a corpse. Disintegrating before my eyes."

Sam's face crinkled in disgust. "Oh, God."

"I wasn't sure if I'd be able to save you," Cas said, the emotions of the day suddenly returning in full force, along with his newfound terror and utter relief that Sam had not, in fact, perished in the portal. It occurred to him that whatever he felt about Dean's loss, the possibility of finding him had not been worth Sam's life.

"I'm glad you did," Sam said, shaking his head slightly. He still sounded spooked and shaken. "Thanks, man. I mean, really, thanks." His hand tightened around Cas's shoulder.

Sam helped him into a chair into one of the bunker's dens, which had a fireplace that was soon roaring (both of them, it seemed, wanted a little warmth and light). Sam also made tea for himself and hot chocolate for Cas, explaining, "Dean likes it. Thought you might like it too."

Cas took it gratefully, and found that sipping the hot liquid did help calm his nerves, if it did nothing for the pain or the tiredness still dragging him down. He felt, irrationally, as if he could close his eyes and sleep until the end of the world.

"Hey, Cas," Sam said, once he was seated in a puffy chair opposite Cas's.

"Hmm?" Cas asked, looking up from his cocoa. (Sam had even put little marshmallows in it, which floated around as they dissolved.)

"I'm sorry, Cas," Sam said earnestly. "For putting you through that. You said it was dangerous for both of us but I didn't listen, and you ended up getting hurt and, and drained. I was so focused on finding Dean that I didn't think about you and I'm really, really, sorry."

Cas put his cocoa aside. The dissolving marshmallows, it turned out, reminded him eerily of the way Sam's flesh had melted away. "You don't have to apologize," he said. "I'm only glad that I was able to pull you out in time. I…understand your desire to find Dean. But I wouldn't want to trade your life to do so."

Sam gave him a tiny smile. "I guess we both shoulda thought of that first, then."

Cas returned the smile briefly before sobering. "You should understand. Dean and I have a profound bond, unlike any I have experienced with any other being. I'm not sure I have a word for what Dean has come to mean to me." He watched Sam's face fall slightly before going on. "But you, Sam Winchester, are my friend. My…best and only friend, as it were. And that is very important too. "

Sam's smile returned. "Well…ditto, Cas," he said, then stared into the fire a few moments before adding, "I mean, Dean's my brother and I love him. But your friendship means a lot to me, too. And we've got to look out for each other, too."

"Yes," Cas agreed warmly. "We do."

Sam sipped his tea. Cas, who was relieved to see that the marshmallows had disappeared from view entirely, sipped his hot cocoa.

"Sam, may I ask you a question?" Cas said after a moment.

"Of course," Sam said, though he appeared to be jolted out of a reverie.

"When Dean died. Why didn't you call me?" Cas asked, the question bursting out before he could question whether it really was a good idea. "Why did you go to Crowley first?"

Sam's face darkened. "Cas, after I brought Dean back here…I knew you had a lot going on. You know, in Heaven. I didn't want to give you another thing to worry about. I thought…" he shook his head, looking down when his eyes brightened with tears.

"I don't understand," Cas said. "Losing Dean would not be a 'thing to worry about.' I wanted to know."

"Yeah. I get that," Sam said, still sounding a little choked. "I guess, I thought…if I brought him back it would just be like it had never happened. That I could just spare you the pain. I didn't know Metatron was going to tell you."

Cas regarded him for a few long moments, as if he could gauge Sam's sincerity in his face alone. "You wanted to spare me," he repeated.

"Yeah," Sam said. "That's all. Plus, you know, not exactly thinking clearly."

"It wasn't that you didn't care to tell me," Cas went on, as the realization dawned. "It was because you…cared about me?"

"Yeah," Sam said again. "And I'm sorry. Really I am."

"You don't need to apologize," Cas said for a second time that night. He rested his head back against the headrest of the chair, feeling the exhaustion pulling at him again.

"Because we're friends?" Sam asked jokingly.

Cas smiled, even as his eyes drifted closed. "Exactly."

When he awoke the next day, still in the chair, he found that someone had tucked a blanked around his shoulders. As the events of the last few days came crashing back to him, bringing with them the deluge of emotions he still had no idea how to process, one thought shone though clearly.

He was very glad that he and Sam could take care of each other.

I hope you enjoyed the story. Please hit that button and let me know what you think!