A/N: Set in Season 5. Lots of eventual Cas!whump and some badass!Cas. A smidge AU, and I will be building upon the revelations/character development established in my previous fic, "The Collector." However, it shouldn't be necessary to read that first in order to get this one.

Disclaimer: I do not own Supernatural or Dante's Inferno. They simply make for entertaining playgrounds. And the only profit I get from these stories comes in the currency of happy feels.

Chapter 1: An Abnormal Hunt

Sam sat at a desk in the Hayward County's morgue with three separate autopsy files spread before him. He'd read in the newspaper about the victims' organs being liquefied, which was how he and Dean had caught the case, but the coroner's detailed notes provided a vividly unappetizing picture.

"Okay, so over the past two weeks, a taxi driver, retired war veteran, and a single woman in her early thirties were found in remote locations, their insides completely turned to jelly." He scrunched up his nose. That was a new one. "Even though it sounds like dump sites, the M.E. hasn't been able to determine foul play. And all the tests for pathogens have come back negative."

Sam swiveled on the stool to face Dean and Cas, who were examining a fourth body that had come in. Well, Cas was inspecting the cadaver. Dean's attention was turned toward the window and the pathologist with long legs and mahogany hair standing in the hall. She twisted her waist coquettishly and stuck the tip of a pen in her mouth. Dean winked at her.

"Agent Stills." When his brother didn't respond, Sam coughed obtrusively.

"Hm?" Dean looked back at him. "What? I'm listening. Coroner's got nothing."

Sam suppressed a sigh. More or less. "Okay, well there's this: one of the reports mentions blue ink in the shape of a handprint. Our vic there got anything?"

Castiel tilted his head to study the twenty-five-year-old male, and reached for the guy's right arm.

Dean finally snapped his attention away from the brunette. "Dude, put on some gloves, remember?"

Cas quirked a brow. "There aren't any contaminants on the body that can harm an angel."

Dean flashed an "everything's good" smile at the lady pathologist, who was still watching them. "Yeah, but you're not an angel right now; you're F.B.I. And agents wear gloves."

He grabbed a pair from a box on the equipment tray and slapped them in Castiel's hand. The angel barely held back a subtle eye roll, which almost made Sam laugh. Cas was picking up too many of Dean's mannerisms.

It was nice having him around more though. He still flitted off in search of God every now and then, but those trips were happening less often and for shorter durations. Sam didn't know whether that was a good thing or not. Was Cas losing faith that he'd ever find his father? It sure seemed like the Big Man Upstairs didn't want to be found, and Sam could kind of understand what that was like. How many times had his dad left him and Dean to go on hunts, sometimes months at a time? At least Cas seemed to finally realize that even if his Heavenly family was screwed up, he always had a home to come back to—with the Winchesters.

Castiel gestured to the corpse. "I was merely going to point out that this body does bear a faint blue handprint."

Sam rose from the desk and went over to look. It wasn't that spectacular looking, more like someone had dipped their hand in paint and then grabbed the victim's arm. "Doesn't look like a tattoo."

"No," Cas agreed. "It's fading."

"So we've got a monster that liquifies people's insides and leaves a blue handprint." Dean lifted his brows. "Ring any bells?"

Sam shrugged, while Castiel continued to stare at the body, forehead creased in his usual deep thought.

"Okay then," Dean said after a moment. "Time to hit the lore."

"Call me when you've identified the culprit," Cas said.

"Wait—" Dean started, but Castiel had already vanished with a swish of air. "Till we get outside," he grumbled, and shot a look at the window to make sure the cute pathologist hadn't just seen an F.B.I. agent teleport out of the morgue. Thankfully, she had returned to her paperwork once Dean had stopped checking her out.

Sam shook his head. Maybe Cas wanted to get in a little God hunting while the Winchesters handled the research.

They headed back to their motel where Sam pulled out his laptop at the room's bulky square table. Dean settled across from him with their dad's journal.

A couple hours later, Dean slapped the tabletop. "I think I got it, Sammy. Dad's got a notation about an abnormal djinn. This bastard off-shoot liquifies its victims' organs and leaves a blue handprint." He frowned. "Remember that second djinn in Magnus's zoo? That was probably one."

Sam grimaced. He tried not to think about that creepy place—or Cas becoming one of those "exhibits."

"Sounds like we have a winner," he said, pulling up a new browser tab. "Okay, so djinn like to hide out in ruins. I'll search for old properties within the radius of where the bodies were discovered."

"And I'll get the lamb's blood."

While Dean took off to ready the weapons they'd need to kill a djinn, Sam started making a list of real estate holdings to check out. Three locations looked promising: an abandoned warehouse, abandoned hospital, and—of course—abandoned shoe factory. He queued up maps and directions to each in his phone and saved them. Then he called Cas.

"Hey, we've got a lead—"

The edges of the curtains fluttered and Sam looked up to find Castiel standing next to him, phone still pressed to his ear. Shaking his head, Sam hung up.

"We're pretty sure we're dealing with a djinn, some kind of cousin or something," he explained, and reached across the table to pick up John's journal. "Everything fits."

Cas skimmed the page. "Have you located it?"

"We have a few possibilities. Once Dean gets back from dipping the silver knives in lamb's blood, we'll be good to go."

Sam set the book down, and then shifted in his seat when Cas didn't move away from the table. The angel wasn't close enough to violate personal space boundaries Dean had been trying to teach him about, but he hadn't gotten the hang of simply relaxing either. And standing ramrod straight two feet from Sam was downright awkward.

Sam cleared his throat. "You want to sit down while we wait?"

Castiel blinked, brow pinching as he swept his gaze around the room. It was one of the nicer motels the Winchesters had stayed at—no peeling paint or frays in the upholstery. A piece of diamond-shaped latticework was erected between the beds and the kitchenette, which even had a coffee maker.

After a moment, Cas took the seat across from Sam, resting his hands in his lap. Sam turned his attention back to the real estate listings in case he'd missed any, but found himself continually glancing at the angel, who looked…tired. Cas was always sporting that rumpled look, but now there were slight shadows under his eyes, and his blue tie looked even more askew.

Sam's mouth turned down. Castiel's falling state was not something the angel liked to talk about. He seemed to waffle between denial that anything was wrong, and writing himself off as completely useless. Hopefully such self-deprecating thoughts had been put to rest the more he aided the Winchesters on hunts. And he'd been helping plenty lately…though now Sam had to wonder if there was another reason the angel had been sticking close.

"Hey, Cas," he said tentatively. "How are you doing?"

Castiel quirked a confused brow. "Fine."

Sam resisted rolling his eyes; he hadn't really expected a different answer, and pushing Cas went about as well as pushing Dean. "You'd tell us if something was wrong, right? If you were having any problems?"

"Like what?"

Before Sam could name any sore subjects, Dean walked through the door.

"Hey, Cas, just in time. We're ready to hunt a djinn."

Castiel tilted his head. "I believe I was here before you, Dean."

Dean paused to throw him a befuddled look. "What? Never mind. Got a location, Sam?"

"Yeah, a few."

They packed up and headed out to the Impala where Cas surprised them both by opening the door and climbing into the backseat. Dean tossed Sam a proud grin before sliding behind the wheel. Sam wanted to smile, but he couldn't help casting a furtive glance at the angel as he ducked into the passenger seat. Cas hadn't offered to teleport them to the locations. It would certainly make the hunt go faster, as they had a lot of ground to cover. Granted, Dean usually refused Angel Air, saying Cas was going to hurt Baby's feelings if he kept up talk like that. The bemused expression on Cas's face had been priceless, and the memory made Sam's lips twitch.

But was Cas learning to do things the human way? Or was the angel gradually losing the ability to do otherwise? He could still fly on his own, obviously, but there was a subtle weight and weariness to his shoulders when he popped in now. Part of the problem, Sam suspected, was none of them knew what slowly falling even meant. Would his powers remain stuck at half-mast, or continue to diminish until he was just an immortal with limited human abilities? Or would he become fully human?

"Hello, Sam?" Dean's voice jolted him out of his thoughts.

He shook his head. "Sorry." One problem at a time. Pulling his phone out, Sam tapped the screen. "Take a left up here."

The abandoned warehouse had been a bust, which was somewhat disappointing. Because wasn't it always a warehouse where the monsters liked to hang out?

It was early evening by the time Dean pulled the Impala into a weeded lot for an old, deserted hospital. Damn, the place was huge. Four stories tall and taking up a whole block. It could take them all night to search the place, all the while the djinn may not even be there, but at the third location melting some poor bastard's insides.

Dean tucked his silver knife behind his back. "We should split up. Work our way around the first floor and then up."

No one disagreed as they approached the doors. Sam stuck his tension wrench and pick in the lock and worked at it for a few minutes before it clicked open. Dean tossed him a pointed look. Be careful.

Sam nodded once. Same to you.

Cas strode down the right corridor without a word, not yet familiar with exchanging silent wishes for good hunting.

Sam took the hallway leading into the center of the hospital, and Dean headed left to sweep the south wing.

Dean hated hospitals—the smell of antiseptic and vomit, the cold, sterile walls, and the pitying glances from staff. There was none of that in this place though. The stench of urine and rat feces permeated the halls, and nearly every surface was smeared with dust and grime. Dean stepped lightly over crumpled trash, probably left over from squatters. A chill hung in the air as the sun outside sank toward the horizon and the temperature began to drop.

He'd covered almost the entire wing and was beginning to suspect "abandoned" actually meant not a single soul was around, when a clatter of metal echoed from a room a few doors down.

"Sam?" he hissed. "Cas?"

No answer. Maybe it was rats.

Another clang shattered the silence. Really big rats.

Dean drew his knife and crept toward a set of swinging double doors. Pressing his back against the aluminum, he angled his neck to peer through one of the oxidized, square windows. Visibility was limited, but he didn't spot any movement. Then his gaze latched onto a gurney in the middle of the room, a body strapped to it.

Son-of-a-bitch.

He slipped inside, doing a visual sweep of what looked like a large triage infirmary. Old beds were spaced along the back wall, with rolling partitions erected between some of them. The room appeared empty. Dean quickened his pace to the gurney, pulling up short at the sight of a bright blue handprint on the guy's forearm. The body was unnaturally still, and Dean hovered a hand over the man's mouth and nose; no breath puffed against his skin. He could've checked for a pulse, but one of the previous victims had exploded when some kids poked the corpse, and Dean did not want blood and guts all over his jacket.

Metal clinked behind him, and he whirled, knife raised. Nothing came flying at him, and there was no sign of the djinn. Maybe rats were creeping about. Yeah, like rats tied this guy down. The kill looked fresh too.

Dean reached into his coat pocket for his phone so he could text Sam that he'd found something. A thin metal pole whacked him across the back, and he pitched forward with a grunt. Pain lanced down his spine, momentarily stunning him. Hands grabbed the back of his jacket and hauled him up. Twisting around, Dean slashed with the knife.

The djinn released him and jumped back. It was a woman, with ebony hair fastened in a tight bun, wearing nice slacks and a silk blouse. She could've been a CEO if it weren't for the glowing blue eyes.

Dean thrust his knife toward her chest. She dodged and darted around to place the gurney between them. Dean feinted left, attempting to spur her into bolting, but she didn't fall for it. Instead, she shoved the gurney at him. The foot of the bed caught him in the stomach, and he almost doubled forward across the victim.

Before he could right himself, the djinn had scooped up the IV pole again and swung it hard. Dean managed to throw his arm up to block, the impact thudding along his ulna. One of the pronged metal legs clubbed his ear, and an array of spots blinded him to the fist that followed. He slumped down the edge of the gurney and was out before he hit the floor.

When he came to, Dean's wrists and ankles were strapped to a bed with those leather restraints used for mental patients. Yeah, he really hated hospitals.

The female djinn stood over him, eyes wild and hungry. Some strands of her perfect hair had dislodged in the scuffle, the frizz adding to the psychotic look.

Dean tested the bonds; the leather squeaked but didn't budge. "So, this is where you send me off to sweet dreams while you drink my blood?"

The woman sneered and leaned forward, putting her face mere inches from his. "Oh, no. My kind prefers a different kind of diet." She inhaled deeply. "Fear, I can smell how rank you are with it."

Dean fidgeted, craning his head away from her warm breath. "You're not a bouquet of roses either, sweetheart."

Gripping his arm, she ripped his sleeve open. "I'm so hungry," she hissed, a crazed desperation filling her eyes. Her splayed hand hovered over him as blue swirls and whorls lit up along her arm.

Dean started to thrash. "Sam! Cas!" Where the hell were they?

The woman backhanded him, and a burst of copper sprang in his mouth. Her features softened, and she lowered her voice as though talking to herself. "Why can't I get enough? A meal used to satiate for days. Now, it barely lasts for one." She flicked her gaze over to the man on the gurney, lip curling in disgust. "I'm famished."

Turning back to Dean, she brought her glowing hand down and clamped it around his arm. He gasped when the inky blue tendrils snaked over her fingers and plunged into his skin, bringing with it a sluggish haze.

The djinn reached her other hand up to stroke his hair. "But you'll be enough, won't you? I can smell it from across the room, the depths of what you fear. It's almost limitless." Her voice petered out as a blanket of fog descended over Dean. Numbness wrapped around his limbs, rocking him in a gray sea until it slowly began to recede.

Blinking, he found himself standing in a motel room, an unremarkable one, just like the hundreds he and Sam had stayed in over the years. The beds looked old and creaky, and a rickety side table three feet tall served as a "desk." Dean's duffel lay open on one bed, half-packed. He scratched his head. Where was Sam? Weren't they supposed to be on a hunt? Had they finished already?

A howl sounded from outside, sending a spike of terror through him. No, it couldn't be…

Low growls and chuffs echoed from behind the closed door, followed by persistent scratches.

Dean backed up a step, heart exploding into overdrive. They'd come back for him.