Castiel shook his head. There was no way in Hell he was going to make Dean trek all the way back to the prison when all Castiel thought he needed was to sit there for a moment and try to collect his energy. He was weak; he was exhausted but for Dean he'd give it his all--what Lucifer had said scared him, that his brother knew the struggle the angel was going through with his feelings, but he wouldn't let that affect him now.
"No! No, I can do it. I can..." He muttered, looking over Dean's shoulder to Jo. "Thank you. When I am better I will think of a way to get you back to Heaven."
"Unless she's here because heaven isn't anymore." Lucifer's voice piped up. "Maybe god really is dead."
Castiel swallowed. "Meet you there, Jo." he said and grabbed onto Dean, closing his eyes and focusing on his target. They were a lot closer than he'd assumed.
What felt like an instant for Dean they were at the prison and Castiel collapsed, feeling completely overwhelmed and unable to keep himself up anymore.
"Reapers... there's reapers... The rooftops..." he rambled, not realizing they were probably vampires or demons. "Not safe, Dean... gotta..." he murmured until his head lulled and he slipped unconscious again.