Prologue:
His coat rustled when Castiel stepped out the darkness of the night to the cocooning circle of the light from the dim street light that stood on the side of the street. He craned his neck to look up to the low grassy hill a half-mile ahead and there stood a lovely two-story house. It was small but cozy and welcoming with the pale blue walls that contrasted perfectly the navy window shutters and doors, complimenting the dark grey tiles of the roof.
It was a house that Dean would have liked to make fun of it. A Marta Stewart's wet dream, Dean had said once when he compared the houses in the suburbs from one old hunting case and Castiel wondered if Dean would've still thought that way if he'd seen this particular house.
He squinted his eyes, discerning the detail easily through the lit window of the house when an ordinary human would had trouble seeing but Castiel wasn't human—not anymore—and his sight surpassed far more, in this plane or the other.
Through the window, Castiel found a Sam's gigantic length moving around the table, setting the plates on the table, his features serious and distant, as if deep in thought. Castiel could tell it wasn't pleasant musings.
Sam looked better. His face was no longer gaunt or sickly and the color of his face had finally returned after all these years. His hair was still long, hanging front of his eyes and he had put weight, Castiel noted, muscular it seemed. Despite the dark thoughts coloring on the hunter's face, he looked less burdened, less hard lines and less something cold shuttering over his eyes but Castiel knew that Sam would never be fully okay.
The troubled look cleared from Sam's face when a woman stepped into the angel's view and his face brightened with a smile that lit within the man. Castiel watched Sam lean down to kiss the woman and hug her.
The angel almost smiled but he frowned instead when he sensed something shifted and rippled—an impending arrival of a presence on this plane.
"This peeping-tom is getting old, even for you." A familiar English voice spoke behind him.
The angel turned to see a former King of the Hell emerge from the night to stand next to him, usually unapologetically sharp in dark suit, gleaming leather shoes and complimentary tie that matched his dressing shirt.
"Crowley." He greeted.
"Cas, Cas, Cas," Crowley chided, dragging the name with each vowel, "You have tasted humanity for a while. Don't you know by now that this stalkerish behavior is rather disturbing and bit creepy?"
"As opposed making ten-year deals to an unsuspecting poor people?"
Crowley snorted, "Trust me, they're far from unsuspecting people."
The angel returned his gaze to the window. Sam was sitting now, talking animatedly to the woman but Castiel found himself distracted. He could feel Crowley watching him, his gaze heavy and intent on his face and somehow it irritated the angel.
"I haven't seen you for seven years. Why are you here?"
"Oh, come on, can't an old chum like me come to see a holy friend such as you—wings and all?"
"You can," Castiel said, "If we were friends to begin with."
"Not even after I saved the world?"
"Not even." The angel agreed levelly.
"Touchy." Crowley muttered with a smirk. "Well at least I tried the pleasantries but I'm afraid it's not my strong suit."
Castiel turned to look at him, his voice flat, "What do you want, Crowley?"
"I have a proposition for you."
The angel tensed. The conversation sounded too familiar for his taste and the memory snapped as terrible déjà vu through his mind's eye where Castiel stood in the lawn, watching Dean raking the leaves at Lisa's.
The tension in Castiel body didn't go unnoticed by Crowley "Don't ruffle your feathers. I'm not here to hash out old deals. It's not like that."
"Then what is like?" His voice was cold.
"I know it's rather unorthodox considering our long, sordid and tantalizing history," Crowley wiggled his eyebrows, "But I assure you, it's for your benefit as much for mine." He paused for a dramatic effect, "I need your help to kill the demons for me."
Castiel frowned, "You must be mistaken. There are no demons here, not for years."
"I would agree with you there but they're not ordinary hell-bound demons. No fire and brimstone." Crowley said, "They're born here, on earth, not from hell. Somehow, someone had found a way deforming human souls into a demon without the help of hell."
The angel stared at the former King of the Hell for a long tense moment, and then he said crossly, "That's not possible."
"I assure, it's entirely possible—difficult but possible."
"Why are you telling me this?"
"I felt like sharing."
"Crowley." Castiel growled and there was a threat behind that single word.
He rolled his eyes, "Fine. If you must know, I don't want demons to roam on earth any more than you would."
His eyebrows furrowed together in confusion, "But you're a demon."
"I was a demon." He corrected with a shrug, "I might have a quarter of it but I'm more human than demon and there's a reason why I shut that gate of hell for good."
"You never told me that reason." Castiel looked up at Crowley with a quizzical tilt of his head, "I wondered."
Crowley smiled bitterly and jerked his head to direction of Sam's house. "If you want to know, go ask Moose. He knows better than anyone."
His eyes were suddenly saucers for a moment, and he tried for a moment and failed not to look at Sam's house, "I'm uncomfortable asking him."
Crowley lifted his eyebrow at this and moseyed closer, "So Moose is right," His voice was heavy with curiosity, "You won't talk to anyone."
"I'm talking to you." The angel said curtly.
"You bloody know very well that's not what I mean."
"Since when you talk to Sam?"
The former demon's single eyebrow rose up, "Since he summons me almost yearly to keep abroad on the supernatural business." He told him, "He says you don't respond his summons, his call or even his prayers."
The angel flinched and looked away.
"And yet you are here, watching over him. Why?" A small pause, "Because of Dean?"
Castiel's jaw tightened.
"Ah, I see." Crowley merely said to fill the space in the silence.
The angel's attention returned to narrow his eyes at him, "If you're keeping touch with Sam, why didn't tell him about this? He's hunter."
"Retired hunter." He pointed out, "Sure, he makes few calls, cover the other hunters' asses, do heavy research and assign cases—the old, miserable drunk would be so proud."
"Sam wouldn't say no."
Crowley grinned, "Would you let him say yes?"
Castiel's dark glower that would scorch the ocean through the depth was his answer enough.
"Admit it; you'll soon burn my eyes out if you let the likes of me find a help from Moose. You won't let him to do heavy lifting."
"Why you don't do the 'heavy lifting' yourself?"
"Please, I'm not the demon I was." He scowled, "I can't go out there and beat my own drums like I used to. Did it occur to you are my best line of defense—no, my only defense?"
Castiel pondered for a moment, looking across the street and the highway beyond to his right. "I can't be your only defense."
"Unfortunately, you're it. After we closed Hell, I'm not at the top dogs anymore. I don't have much asset over the usual monsters or enough power to shut down the earthbound demons."
"I shall I assume this matter proposition results ulterior motive from you?"
"No hidden agenda." Crowley shrugged. "I just want those demons gone. Vamoosed."
The angel looked skeptically at him, "I find that difficult to believe. If there something I learned from you, nothing ever comes free and there's always price at the end of the day."
"Unfortunately, I'm afraid the price of the deal is going be us. It's not going be easy, stopping those people—assuming they're human—who's creating these demons in first place."
He stared unblinking at Crowley, "How you do know?"
"Call it a gut feeling." Crowley leaned forward, his voice dropping an octave lower, "Beside last time someone created demon on earth was Lucifer, the first being Lilith." The angel flinched at the name, "With that regard, it's easy to assume someone that's doing the entire ruckus is powerful, hence you on the scene—a precious angel who might be mite more powerful enough to smite them."
He looked troubled but didn't argue. "How they're doing this?"
The former demon's lips stretched into an oily smile, "Should I take by your question that you're in?"
Castiel hesitated for a pause, considering the implications of the situation. If Crowley was right, then it needs to be taken care of as soon as possible, but first, he needed evidence before diving down the situation headlong—a proof enough that Crowley is not misleading him, a proof of the existence those earth-born demons and how they're made of.
Deciding there was one way to find out, Castiel said, "It means I'm listening."