Day Three: Blood Loss. Cas hates being unable to cure Dean now that he is human, but a small perk is being able to hear Dean's thoughts when he's drunk on blood loss.

Title: I'd Believe It

Bright, white light flooded the living room, blinding Cas. He held an arm over his face and screwed his eyes shut as the angel screamed before disappearing, ejected from the room. When the light subsided and Cas raised his arm, he saw Dean, laying on the floor, beside an Enochian warding made from his own blood. "Good thinking," Cas said, but Dean didn't lift his head to respond, "Dean?" he remained still, "No, no," Cas's heart skipped in his chest and he rushed to Dean's side, taking him by the shoulder and turning over his limp body.

He had cut open the back of his arm and the entirety of his forearm was red and dripping with his own blood. His mouth was slack and his skin was waxy and pale. "Please, Dean," Cas held him by the shoulders and shook him. Dean's eyes fluttered open.

"Cas?"

Cas relaxed. "Are you okay?"

"What happened?" his forehead creased as he craned his neck to search the room.

"You lost a lot of blood. Can you sit up?"

"Yeah," Dean placed a hand on the wood floor and tried to push himself up, but his arm faltered and he crashed back down.

"I've got you," Cas said and wrapped an arm around his back to lift him. Dean cringed and held his wounded arm against his chest.

"I feel kinda weird," Dean sounded dreamy.

"You'll be fine," Cas assured Dean, but there was a tightness in his chest. If he were still an angel, all he had to do was touch Dean and his injuries would be healed and his blood restored, but he was impotent. What use was he to any of them? Seeing Dean like this and being unable to help, it ached him.

He assisted Dean to the couch and propped his legs on the sofa so he could lie down. "Cas…" Dean rasped.

Cas crouched next to the hunter. "Yes, Dean?"

"Thank you."

Guilt filled Cas's stomach and he swallowed thickly. "I'm sorry. I'm useless."

Dean frowned. "You're not useless," the words were slightly slurred, "I don't know what I'd do without you."

"But my powers…"

"Powers or not, I don't care," Dean reached out a hand and lazily patted Cas on the face, "I love you, buddy."

Despite his shame, Cas couldn't help but break into a smile. Dean was far from the most affectionate human, so Cas knew this was a side effect from the anemia. "I love you too, Dean."

"I'd go crazy if it was just me an' Sam all the time. He's great, but sometimes I think I might kill him if I didn't get a break."

Cas chuckled. "Well, I'm glad to be of service."

"You're not just helpful. 'S more than that," Dean yawned.

Cas could have let it go. There was no way to know if Dean really meant what he was saying, or it was the inebriated side effect of the blood loss. Dean might even regret his kindness when he was back to normal, but Cas craved to hear whatever came next. "What do you mean?"

""Dunno. 'S like, ever since I met you, I've got more of a…" he searched for the word, "future. It scares me," he said and suddenly sobered.

"What does?" Cas pushed.

"You being human. I can't- You can't die," he stared severely at Cas and grabbed his tie, yanking him closer. Cas could see his stubble, the lines around his mouth, his chapped lips. "Promise you won't die."

He wasn't sure if it was imprudent to lie. It wasn't something he could guarantee, but seeing the distressed look in Dean's eyes, he had no choice. "I promise."

Dean released him and melted back into the couch. "Good."