"So, how's life been since I died?" Castiel and Dean were sitting in a 2120 Impala, staking out a house in the suburbs that had all the hallmarks of an open-and-shut haunting. A young woman had been killed in the house and was now slicing open anyone that was roughly similar to her murderer. The bones had been thrown onto a trash launch, and they couldn't salt and burn them because they were light years away. Cas had wanted to leave, but Dean had convinced him that they should hunt while they made a plan to get the souls out.
"Not a lot." Cas didn't look at Dean.
"Not a lot?" The demon sighed. "It's been centuries, man, you had to have done something. Didn't you get bored?"
"I am as old as time itself. I find that it is like sand; it can be observed in any amount, whether a few grains or an entire ocean floor." Cas wondered if the humans had cared for the Earth, and if there were still beaches. From what he had seen, the world had been mostly machines and computers and robots, with a duck pond or tree scattered in here and there.
"So, you're saying... what, exactly? You don't get bored?"
"I am a multidimensional being, therefore it is hard to understand the concept. Perhaps mortal things feel boredom because of the limited amount of time they have. Any period of time spent idle seems a waste."
"I never did get straight the whole angel-emotions complex. I know you feel something, or you'd have no point." Dean wished for something to do with his hands. Cars relied mostly on thought waves for direction, eliminating the need for a steering column. One could get in a car and drive for hours without pressing a single button.
"We were created to be God's mercenaries, carrying out orders no questions asked. But angels, being divine and superior to all other creation-"
"Still modest as ever, Cas-"
"-learn and absorb knowledge. So when humans were given free will and emotions, we picked up on them. But it's rather like being in a foreign land with only a pocket dictionary of the language." Cas watched a large house cat cross the street, marveling at its gorgeous coat. Evolution and the advances in veterinary medicine had been quite favorable to pets.
"Like memorizing your times tables and then taking Calculus."
"Exactly like that. Mostly, everything blends together, positive with positive, negative with negative. I know if I feel Bad about something or Good about something, and I go from there."
"So, you've just been hangin' out these past couple of years?"
"I created a haven where nothing can find me. Only humans and I can enter."
"Why don't you want to be found?"
"There are some angels who are rather like your human bounty hunters. There's a huge reward for anyone who kills me." Castiel's voice broke. "I'm in huge danger just being here."
"So why are you?" If Cas couldn't feel boredom, then something else must have been keeping him here.
"You asked me to."
Castiel looked at Dean for the first time in hours. He still had trouble seeing past the demonic aura which blocked most of Dean's appearance from view, and it made him feel Bad to see his old friend so defaced. If he focused hard, really wanted to, he could block out the ugliness for a moment, and he used this to catch a glimpse of the face he had missed so dearly.
"If you're in danger, then we can go back-"
"No. Humans only. I want to stay here."
"Why?"
"I missed you," stated Cas simply.
"Cas?"
"Yes?"
"I missed you too. Oh my god, I missed you. I assumed since you didn't try and find me that you were dead, as in 'ceasing-to-exist" dead, not Sam's dead which is heaven, and that was worse than anything I faced in hell."
"So can you? Feel emotions?"
"Yes."
"What do demons feel?"
"Everything, ten times more potent. Ambition, anger, regret, confusion, sorrow, doubt."
"Anything Good at all?"
"I'd given up, but then-"
"Dean, I think the ghost is moving." Cas pointed at a flickering light moving inside the house. Dean heard the familiar ruffle of wings and he was left alone in the car.
"...I found out that you were still alive," he finished aimlessly, watching Cas walk away.