Author's Note: This fic was requested by CeliaSingsSongs and was inspired heavily by another Purgatory fic I read (simply called 'Purgatory') by Kaoz. You should go check it out. The plotlines are 100% different and our writing styles are too so it won't spoil this one for you at all, but it is a really good read and a cool take on Purgatory.

Second note: Just a head's up that this fic is NOT slash (sorry, no Destiel or Denny) and is NOT a Dean/OC fic (despite my tendency to hook that guy up, lol).

~X~X~X~X~

Chapter 2 – Finding Nemo

A week passed and Castiel kept moving, always trying to stay one step ahead of the Leviathan. If they were focused on him then they weren't hunting Dean so he kept running. Stuck in this God-forsaken place, it was the only thing he could do that would give his life any value or purpose. There was only one innocent here for him to protect.

He was strolling along a narrow path through the endless expanse of trees when he sensed something watching him from the cover of a rock. He came to a halt and tilted his head slightly, trying to figure out what manner of creature it was. Not a vampire… not a ghoul… not an Arachne. It felt like… no, it couldn't be… there weren't any of those in Purgatory.

He winged himself over fifty feet so he stood right behind it and a small, almost disappointed sound escaped him when he recognized the creature as a Crocutta, loathsome creatures even by Purgatory standards. He slammed a hand forward, palm-out as it turned to face him, making contact with its forehead and drawing upon his heavenly power to kill it.

Startled when the creature's eyes turned black, Cas hesitated. An instant later, black smoke began to jet out of its mouth, gushing past him and soaring into the air.

It was a demon! Here, in Purgatory!

He gave chase immediately, winging himself after the fleeing hellspawn. It was hard to track in freeform and he lost it fairly quickly, but he wasn't worried. It would have been difficult to tackle midflight anyway and a demon couldn't stay loose forever. It would need to find a host. Then he would be able to find it.

He crouched down in a small glade to wait, keeping his senses sharp and feelers out both for signs of the demon and for approaching Leviathan. A frown knitted his eyebrows together with worry at this strange turn of events. What was a demon doing here in Purgatory? Was it after him? Or worse, and far more likely, after Dean? He sighed. How could he keep Dean safe from a demon if he couldn't go anywhere near him? He couldn't protect his friend without further endangering him.

Three hours later, shortly after dark and after yet another prayer from the hunter had gone unanswered, Cas got a sensory line on the demon and winged after it instantly. He found it in a shapeshifter, its form that of a blonde man in his late thirties.

He curled his fingers around its neck and, this time better-prepared, slammed his other hand over the creature's mouth before the demon could escape. The possessed shapeshifter squirmed and writhed in his grip, eyes black as the moonless night sky.

"You are a demon," he stated flatly, retracting the hand covering the man's mouth just enough to let him talk.

"No shit. Give the angel a freaking cigar."

The demon gave up his struggle and sagged into in the angel's strong hold. Cas pushed it up against a tree and took a step backwards, ready to react if it tried to smoke out.

"Demons cannot possess monsters. Their souls are too twisted, too damaged."

His captive shrugged. "You'd be surprised how adaptable we can be when we're out of options."

"How did you get here? Demons do not belong in Purgatory."

"Last I checked, neither do angels."

Cas scowled, trying to appear threatening.

The demon raised his hands in mock submission and shook his head. "Really, Castiel? Am I that forgettable? You were standing right there when Crowley used me as a crash test dummy for his fucking door."

Cas managed to keep an impassive expression on his face despite his shock at the revelation. He remembered. Before discovering the correct spell, he and Crowley had been trying many different ways to open a gate to Purgatory. They had actually succeeded in opening one questionable portal but it was small and unstable and they weren't even sure where it led. Cas suggested they test it and, without a second thought, Crowley threw one of his own minions into the shimmering void. The hole disappeared immediately afterwards.

The sacrificed demon had been a young woman. "You were possessing a human at the time," Cas accused.

"I've moved on."

"And the human?"

"Who cares?"

"I do. Where is your vessel?"

The demon snorted, giving Cas a jeering look. "You didn't give a damn about her when Crowley tossed us in here."

Cas flinched, remembered watching impassively as Crowley threw the demon in the hole, never sparing a single thought for the innocent human inside.

"Is she still alive?" he demanded, taking a step forward that was again intended to be threatening.

"She was when I left her," the demon fired back, looking more annoyed than scared.

"Why did you leave?"

"Because a vamp got a hold of us and let's just say he wasn't fond of my kind."

"Of demons?"

"No, of unicorns."

Cas frowned at the sarcasm but the demon simply rolled his eyes before continuing. "Crazy bastard kept exorcising me over and over."

"How does one exorcise the same demon repeatedly?"

"You know, for an angel you're pretty fucking clueless, mate. You can't exorcize a demon to Hell from Purgatory, at least not with your standard invocatio. The words hurt like a son of a bitch but they don't open a door from here. After getting an hourly dose of that for two months… let's just say I didn't feel like sticking around. First chance I got, I split."

"And the human?"

"Far as I know, psycho-vamp still has her."

"How do I find this vampire?"

"Fucked if I know! His name's Walker. George or Geordie or Gordon or something Walker."

The demon took a step forward off the tree. "Listen, angel, we're in neutral territory here so what do you say we just agree to co-habitate? I'll leave you alone and you leave me alone?" he bargained.

"No. I think I should do away with you."

"Whoa, whoa, wait." He raised his hands in a placating gesture. "Can't exorcize from Purgatory, remember?"

"I don't exorcize," Cas said evenly. "I smite."

He stepped forward and slapped his palm against the shapeshifter's forehead, sending a blast of power into the creature before the demon could escape. Flashes of orange shone from beneath the skin before the body slumped to the forest floor, dead.

Castiel pursed his lips in thought, contemplating all he had just discovered. His priority thus far had been to keep the Leviathan threat focused on him and away from Dean. After that, he had no purpose here but to suffer and repent. There was no good he could do in a land of monsters. Saving vampires from Rugaru or vice-versa made no logical sense and served no greater cause. More importantly, it offered him no redemption for all the wrong he had done.

But if there was another human, one he had played a hand in sending here nonetheless... well, that was a mission with purpose.

Yes, he thought with conviction. He would find the human and rescue her from the vampire. Besides Dean, she was the only innocent in this place. It was only one soul, not enough to even make a dent in his path to redemption, but it was something.

Glad to finally have a mission beyond survival, he set out to find her.

~X~X~X~X~

In between brief but violent bouts with Leviathan, the next few days were spent seeking out vampires and interrogating them before sending them to their death – or final death, or nothingness, or whatever happened to a soul killed in Purgatory. Vampires were an unfriendly lot, loyal to the death to those they considered nest-mates but barely social beyond that circle. It was slow-going and a trail of fanged bodies were left in his wake, but Cas began to piece together information on this vampire named Walker.

The name was Gordon Walker. He was anti-social even for a vampire and had no nest-mates. He live alone, traveled alone, and hunted alone. It was said he hated all monsters but most of all vampires and was known for killing his own kind. It seemed to be the general consensus that Walker hated vampires so much that the only thing stopping him from cutting his own head off was the fact it would prevent him from killing other vampires.

Information on his human captive was more scarce. One unfortunate vampire in the angel's clutches finally admitted she had heard that Walker had a pet human at one point, but that had only been for a few months and he had lost her to Luthor over a year and a half ago.

"Luthor?" Cas demanded harshly. "Who is Luthor?"

Luthor was the leader of a large vampire nest whose territory extended from the Plains to the three-forked waterfall. Apparently, he had kept the human for about a year, using her for food, entertainment, and bragging rights until a horde of ghouls attacked, trying to steal her. Cas's vampire prisoner didn't know if the ghouls got her or not, only that Luthor was 'seriously pissed off' when he lost his prize.

Cas thanked her politely for the information and promptly killed her, not bothering to look down as her body sank to the forest floor at his feet. It would seem he had no more use for vampires. He would now have to move on and start seeking out ghouls.

Logic was nagging at him to cease this futile effort because if the ghouls had taken the human, they would not have fed on her in small doses as the vampires apparently had, allowing her to replenish her strength and blood between feeds to make her last. No, the ghouls would simply have devoured her, tearing flesh from bones until there was not a scrap left. He pushed the negative thoughts aside and kept following the trail.

As he set out, he wondered briefly if this was what Sam and Dean felt like when hunting, if they felt that very same sense of satisfaction every time another piece of information was discovered, another stone unturned. He had to admit, it held a certain appeal.

~X~X~X~X~

It took two days to find the den of ghouls. They were elusive creatures who stayed underground much of the time and kept to their own kind. Cas marched directly into the middle of the nest, smiting left and right and demanding to know where the human was. He was met with nothing but desperate pleas and frantic denials of knowing anything about a human.

It wasn't until he reached the leader, a pale, bloated beast in the ghoul's true form, that he received a useful answer. Between sobs and whimpers, the ghoul admitted trying to capture a human from Luthor's nest as a gift to their former leader but not being successful. It was believed the girl got away in the melee.

Cas killed him and left the den, quickly seeking a quiet hideout where he could rest and replenish his strength. Smiting over twenty ghouls in a row had almost completely drained him. There was no direct link between Heaven and Purgatory for him to form a connection so his power here was limited and slow to renew. He found shelter in a small thicket and sat down heavily on the grass.

Perhaps the human female was already free. Perhaps she had no need for him or his help after all. Or perhaps, and this was the most likely scenario, she was already dead. A lone human in this environment would be hard pressed to last a month. Cas was loathe to admit it, but the same applied to Dean. Cas could keep the Leviathan away from his friend but the remainder of Dean's days would still be spent in a bloody, desperate, non-stop fight for survival. A female human without Dean's strength and skills stood no chance.

At least when it came to Dean, he could check-in on his friend from time to time. He would wing in for brief moments, keeping enough distance the hunter didn't see him and watching for just long enough to assure himself Dean was alive and healthy and his new questionable traveling companion hadn't turned on him. Dean also kept up the nightly prayers, ever loyal and hopeful despite getting no response for five weeks now.

Cas did not know the other human. He had no connection with her and therefore, no way of finding her with what Dean referred to as his 'angel-mojo'. He sighed, resting his chin on his knees, bent up before him. He would keep looking. She was most likely long-dead but on the off-chance she wasn't, he would keep looking. She was, after all, the only means of redemption available to him in this land of monsters.

~X~X~X~X~

It was another full week before he found her. It was dawn and Purgatory's bleak, pale sun was just peeking through the forest cover when he felt an unmistakable human presence wrapped up in a wave of fear. He winged towards it, showing up to find the tiny human backed into a narrow crevice between two large rocks in the side of a rocky slope, jabbing a makeshift blade wildly at a snarling Gogmagog clawing at her from the front. The beast's Rugaru master was moving around to climb the steep banking and come at her from the other end of the crevice.

Cas cut off the Rugaru, making quick work of it and dropping it to the ground with lights still dancing behind its eyes. As he moved towards the hairy beast still trying to force its way between the two rocks, he briefly regretted the pacifist phase he went through right before being hurtled to Purgatory. This would have been easier had he been carrying his angel dagger. Gogmagog's were strong, vicious creatures resembling a cross between a gorilla and a wolf. Cas reached out and grabbed its tail, dragging its front end out of the narrow opening. As soon as it twisted towards him, its large fangs snapping wildly, he lunged forward and grabbed it by the head with two hands, staggering backwards as he summoned his power to kill it.

It hissed and writhed for a second before sagging lifelessly in his grip. He tossed it aside and lifted his head towards the crevice, trying to see the human crouching in the darkness. As he stepped forward there was a sharp zing sound and an arrow shot out of the opening and sank into his chest. He stopped and peered down at it, caught by surprise.

"I mean you no…" He cut off his declaration of peace when another arrow flew straight towards his left eye. His hand shot up and caught it mid-air, barely an inch from its mark. He threw an annoyed look at the unseen human in the darkness, pausing to exhale loudly as he pulled the arrow out of his chest also. "I mean you no harm," he finished.

He got no reply and she had moved so far back into the crevice Cas could no longer see her. She was most likely terrified so he decided to be patient and make sure not to scare her further. He would gently coax her to come out of her own free will. He took a step backwards and spoke calmly into the crevice. "My name is Castiel. I'm not going to hurt you. I am an ang…"

He was cut off once more, this time by a small dagger flying through the air again aimed at his left eye. He jerked his head sideways and let it soar past his ear to jab harmlessly into the forest floor. It had come from above and he looked up sharply to see the human on top of the rocks that had formed the crevice. She must have climbed out the back of the nook and rather than risk exposure by climbing up the steep banking beyond, she was going to go on the offensive, coming at him from above. Since he stood between her and quick escape into the forest, she was going to attack.

He furrowed his brow at the futility, not to mention stupidity, of attacking an angel head-on before it occurred to him she probably thought he was a Rugaru. After all, they did usually come in pairs. In Purgatory, the only failsafe method of killing all manner of creatures was decapitation and sure enough, she launched her tiny form at him, a homemade scimitar swinging in a smooth, wide arc aimed right for his neck. A fierce scream he likened to a battle-cry escaped her as she bore down on him from above.

He winged sideways, reaching out as he did so to snatch the weapon from her grip and toss it aside. She landed on the ground with a thud and rolled swiftly to her feet, spinning to face him. Her eyes were wide and wild and her body tense as she took a fighting stance, her hand already reaching for another dagger from a holster on her leg.

In the heartbeat that followed, Cas got his first good look at her and was taken aback. He hadn't seen a human in this state for a millennium. She was filthy, both her clothes and her face streaked with dirt. Her tangled hair was long and brown, pulled haphazardly into a high ponytail that made her look much younger than he remembered her to be at Crowley's warehouse. She was small, barely reaching chest-high on the angel. Her clothes were ripped and shapeless and had conspicuous bulges indicating concealed weapons of every variety.

"I mean you no harm," he said quickly, hoping to fend off her next attack before it started. He lifted his hands in a gesture of peace. "I'm not going to hurt you."

She never moved a muscle. Remained silent, eyes never leaving his.

"I am an angel of the Lord. I've come to help you."

Again no reaction; she just kept staring at him, blade held out threateningly in front of her.

"That weapon will be of no use against me," he pointed out. "Attacking me would be futile."

She never even blinked. Cas sighed and reached out to her mind, prodding just enough to find something useful. "Your name is Nia," he stated, pulling back, thankful his limited powers could find that much. "I have sought you out to try and help you. There is another human…"

He let his sentence trail off when he heard a sound behind him. Turning his head he caught sight of another Rugaru, this one female, charging towards them with blade drawn. Must be the mate of the dead Rugaru. After all, they usually travelled in pairs.

He spun around and strode towards their attacker, arm outstretched. He sidestepped the swing of the blade the flesheating monster carried and put her down angel-style, his usual intense expression on his face. When the Rugaru fell to the ground, Cas turned back towards Nia only to find her gone. A glance to his right caught a glimpse of her disappearing into the cover of the trees.

He pursed his lips in frustration. Had he not just saved her? Twice? Why would she flee? Whatever the reason, he couldn't leave her alone in this hostile environment. He needed to help her, to save her in some grander capacity in order for it to count for anything.

He winged himself in front of her, standing his ground as she skidded to a halt with a gasp, the scimitar she had swung at him earlier gripped tightly in her fist.

"Please don't run," he said. "I'm trying to help you."

She replied by swinging the blade, again aiming for his neck. It struck him but he got his arm up before it could do any real damage. He snatched it from her hands for the second time and scowled as he wrapped a fist in the front of her baggy coat and lifted so her feet were barely scraping the ground.

"I. Am. Not. Going. To. Hurt. You." He said it sternly; his patience was quickly waning.

She wriggled and squirmed and kicked out at him trying to get loose but he simply held her tight, waiting for her to give up. After a few moments of violent squirming, she finally fell still save for her heavy breathing. Her eyes rose slowly to meet his, defiance still lurking in their wild depths.

"I mean you no harm," he repeated, trying to rein in his annoyance. When he still got no answer he cocked his head slightly sideways in sudden curiosity. "Can you speak?"

She narrowed her eyes at him and nodded.

"Do you not understand I'm trying to help you?"

She made a sound that resembled a snort and one corner of her mouth lifted in a hint of a smile.

Cas frowned. "You don't believe me? Did I not just…"

"I remember you."

She spoke. He would have been pleased had her words not delivered him a renewed rush of guilt.

"You and Crowley, dancing," she said with a laugh, though her eyes held no mirth.

"Dancing?" Cas wasn't sure what she meant by that but he had no doubts she remembered his involvement in her being thrown into Purgatory over two and a half years ago.

"I was invisible," she accused. "You saw the demon."

Cas figured out what she was getting at and he sighed. "I am sorry," he told her. "I should have protected you and driven the demon out of you instead of worrying about my own agenda at the time. I can't take back what Crowley and I did to you... and for what you have been through since that day, I am truly sorry."

He meant every word of his apology.

Her hard glare softened slightly and he was encouraged enough to lower her to the ground and unwrap his fist from her coat. When he took a step back, she stayed where she was but kept her amber eyes fixed on him.

"I have committed grievous mistakes and made unfathomable choices that I regret deeply but cannot erase," he admitted openly. "What happened to you was but one of those. It is, however, the only one I can currently try to remedy in some small measure."

They stood in silence for a long moment, Castiel lost in silent reflection of his past mistakes and Nia studying him closely the whole time.

"I have heard of a means to escape Purgatory," he informed her finally, referring to Dean's planned way out. "Since you are human, there may be a way…"

"Not real," she said with a shake of her head. "Rumor."

She sounded so sure. Cas had thought it a long shot anyway but had hoped it held some validity for Dean's sake. He nodded. "Maybe so," he continued, "but there is another human here. His name is Dean Winchester. I shall take you to him and he can help protect you from…"

"No."

"He is skilled and capable and…"

"No."

"You cannot survive long alone."

"Survived so far. Better just me. No other humans."

"He will not hurt you."

"But a thousand others will with his stink around."

Cas tilted his head in thought. This human was strange, even by the angel's standards, but he had no trouble following her meaning. Dean's humanity was surely attracting a constant stream of unwanted attackers in this place, as was Nia's, but she had more confidence in flying below their radar and going unnoticed alone than as a duo. He had thus far resisted the urge to scrunch up his nose at how foul she smelled, which he realized now was an attempt to cover up her distinctly human scent in a land of monsters with heightened senses of smell. He knew it would not work entirely since her humanity was more than just a physical smell of blood and sweat. These creatures could smell her pure, clean soul.

He continued his argument, trying to persuade her to let him take her to Dean and travel with the capable, seasoned hunter but she adamantly refused, speaking mostly in one or two-word sentences but never wavering on her position. Finally, he gave up, acknowledging the validity of her argument that two humans together would attract far more attention than two single ones. With nothing else to offer her, he apologized once more for sending her here and made to leave.

"Wait," she said, taking a hesitant step closer. "Can't you stay?"

He shook his head. "I will bring more danger upon you than you can imagine," he said honestly. "The Leviathan are after me. I have a price on my head and they will stop at nothing to find me and kill me."

"What's Leviathan?"

"The oldest beings in Purgatory," he informed her. "And the reason it was created."

"I can help you kill them."

He gave her a skeptical look. "They are a far worse foe than a Rugaru couple," he admonished. "You cannot stay with me."

Her face fell and she suddenly looked tired and sad and… so innocent. Cas's guilt meter spiked and he reminded himself of his purpose in seeking her out. "If you are in trouble," he told her slowly, "just pray to me. I will find you if you pray to me."

She looked baffled. "Pray?"

He nodded. "Yes, pray. Aloud or silently. I will hear you."

"I prayed for a year with that demon inside me. Nobody answered. I prayed for another year when Luthor had me. Nobody answered."

Cas gave her a long, purposeful look. "Pray to me. I will answer."

With that he disappeared.

~X~X~X~X~

Author's Note: I'm sure you all remember Gordon Walker but just in case any of you didn't remember Luthor, he is the vampire John Winchester shot with the Colt in season 1 to test it. Dean and Benny join the story next chapter. (this is NOT a Dean-OC fic).