Sam had somehow snuck out a chilled IV bag, an IV stand, and a cooling blanket out of some clinic on the outskirts of town. He put the IV in and wrapped the cooling blanket around his brother.
Soon, the light in Dean's eyes dimmed and he opened his mouth. The same blue smoke as before drifted out and went into Castiel. Castiel's eyes flew open as Dean slumped over. Cas stood up and helped them maneuver Dean onto the couch.
After they put him down, Sam pushed Cas into the wall and held him up by the collar. "What the hell did you do?! This wasn't supposed to happen."
Cas wasn't phased. "I didn't expect this to happen. I've never merged with a human before. It must have been too much for him. I don't know..."
"Can you fix him?" Mary was kneeling beside Dean, holding his hand.
"My grace is what did this to him. Any more might kill him." Sam let Cas go then and walked to the table where he'd put a thermometer. He silently slid it into Dean's mouth.
No one said anything. It was like they were waiting for a death sentence. It beeped. 107. "Dammit. 107 degrees is where most people die. Dean is strong, but if it goes any higher, he'll die." Sam pushed his hair back. "Uh, Ruby go get ice. Lots of it. We need to put him in an ice bath."
• • •
This time it was Ruby and Castiel who stayed in the doorway. She figured Dean wouldn't want her in there. Mary and Sam pushed Dean under the icy water. After what seemed like forever, he gasped and woke up. He looked around frantically. Ruby had never seen him look so freaked out.
He locked eyes with Castiel, but then his eyes started to roll back; he'd passed out again. Sam checked his fever again. "It's down to 105. We should leave him in until it goes down more."
Mary held his head above the water until they decided to get him out. Castiel said he would take him to the bedroom. He picked him up effortlessly. Mary trailed behind with the IV pole.
• • •
Dean woke up the next morning. Everyone except Castiel was asleep. Cas said he doesn't sleep, so he kept watch over Dean. He changed the washcloths when he needed to and took off the cooling blanket when Dean's temperature was back to normal. Then, he put the comforter over him.
When Dean woke up, he jerked and reached under the pillow for a gun.
"Sam told me you might do that." He took Dean's gun out of his trench coat and gave it to Dean. He put it on the bedside table and slumped back into his pillows, his breathing hitched.
The talking woke up Mary. She had been asleep in the chair next to the bed; she didn't mean to fall asleep. Sam and Ruby were in the bed next to Dean's.
"Dean?"
"Mm. Hey, Mom." His voice was horse and his breathing was still strange. He kept his eyes closed.
"What do you need?" She didn't bother asking if he was okay.
"Headache," was all Dean said.
"Would you get Dean something for the pain, Castiel? I think there's some pills on the table." She turned to wake up Sam and Ruby. She touched Sam's arm. "Dean," he muttered sleepily before opening his eyes. He sat up which woke Ruby up.
Sam went right to Dean. "Dean? Can you hear me?" Sam touched Dean's shoulder and started to take his pulse.
"Yeah, but I wish I couldn't." He took his hand out of Sam's grip and groaned. "I've got a killer headache." Dean pinched the bridge of his nose. His eyes were still shut tight. There was bright light coming through the blinds. Ruby went to close them. She used to get migraines, so she knew how much worse light and sound made them.
Castiel came back in with a glass of water and some pills. "Take this, Dean." Something had changed in Castiel's voice.
Dean sat up and opened his eyes. Castiel dropped the pills into Dean's open hand. He handed the glass to him carefully. Their fingers touched accidentally. Ruby sensed a change in both of them.
Ruby sat on the end of Dean's bed. She could tell that Sam wanted make sure he was okay, but Dean kept insisting he was fine. Sam finally sat on the bed next to Dean's. Mary stayed in the chair next to Dean. Castiel stood a few feet from the door.
"Dean. Do you remember what happened?"
"Yeah." Dean's voice cracked and he cleared his throat. He looked up at the angel. "I think it's safe to say that we can trust Cas."