Kinda short angsty piece, because I've had the image stuck in my head for about a month now. A bit AU, I suppose, if that's how you want to look at it.
Everyone was starting to worry about Castiel, and they agreed, at Sam's immediate request, that Dean should be the one to check on him. Of course they would, the bastards, he silently mused. Profound bond, my ass. They just can't imagine him not being an angel anymore. Dean refused to think of him in that sense. He'd saved their asses more than a few times, and if he deserved anything, it was respect for all that he'd sacrificed for them.
Dean pushed open the door and peered inside. He smiled at first, seeing that Cas had plugged in the little seashell nightlight that had belonged to the previous owner of the room. It cast a soft pinkish orange glow against the wall. His smile started to droop when he picked Castiel out of the shadows, sitting on the edge of the bed and absently turning his angel blade in his hands. In the light from the seashell Dean could see his eyes sparkled with tears he was trying to keep in. He stepped inside and quietly shut the door behind him. If Cas was about to lose it, Sam and Kevin didn't need to know.
He sat on the edge of the bed next to Cas and turned to cautiously study him. He didn't say anything, fearing whatever came out of his mouth might not sound as comforting as it should. He didn't want to take any chances and further upset him. Now that he was human, susceptible to mood swings and extremely impulsive actions, anything and everything could set him off. Dean knew Cas hadn't been doing well when they'd picked him up and brought him home. He'd been living off the kindness of strangers, who were few and far between, and the weather hadn't been the greatest as of late. When they found him outside a gas station in the middle of nowhere, his hair was plastered down to his skull in the rain and it took hours with several blankets wrapped around him before he stopped shivering. Cas tossed the angel blade into the chair across the room. Dean saw a tear slip down over the angel's cheekbone and heard a soft sob. Cas was trying hard not to show the new weakness he felt, the guilt of everything he'd done swallowing him whole.
Dean put a tentative hand on his shoulder and felt the tremors. Cas instantly latched onto his hand like it was the only thing left in his world and pulled Dean into a crushing embrace. Dean threaded his fingers through the short hair on Cas's neck, gently cradling his head while the angel wept into his shoulder. His other hand came to rest at the small of Cas's back, pulling him a little closer. Cas was falling apart in his arms, and he felt absolutely worthless.
"I've sentenced them all to death, Dean," Cas sobbed, his fingers tightening in Dean's shirt. "They can't survive in this world, they don't know how."
Dean rubbed little circles into his back and buried his nose in Cas's hair. It smelled like his own mint shampoo and underneath, just barely hanging on, ozone. Dean guessed that that smell would never completely come out, worked far too deep into Castiel's pores.
"There's nothing I can do. Nothing." The angel looked up at Dean, his blue eyes bloodshot and weary. "Metatron made me betray my brothers and sisters, and now they're all homeless and it's my fault."
Dean leaned forward and gently pressed his lips against Cas's forehead. Burning up, he noted. He couldn't get out of the rain. "We'll figure something out," he whispered. "Every spell can be reversed, it's not like this one's any different."
Castiel was quiet for a moment, tears still pouring from his eyes. He pushed up and ghosted his lips over Dean's, mumbling an almost silent thank you before pressing his face back into Dean's shoulder. Dean carefully leaned back into the bed, taking Cas with him. He held him as Cas continued to cry, sobs wracking his feverish body. He was glad he'd closed the door when he came in. Cas eventually grew quiet and his breathing evened out. He shifted and tucked his arms into his chest against Dean's side, his head pillowed on Dean's arm.
Once he was sure Cas was asleep, Dean let his own tears come. His thoughts echoed Castiel's words. I should have been there for him. We all should've known Metatron couldn't be trusted. He has nothing now and it's my fault. The angels will come and kill him for what he did. He wrapped his fingers around Cas's wrist, feeling the reassuring pulse underneath. He fell into a restless sleep, waking early the next morning when the angel next to him started to sneeze.