"Hold up, Cas," Dean said as he hurried along the corridor leading to the garage. The angel turned and regarded him solemnly. "Look, are you OK, man?"

"I'm fine," Cas said stiffly.

"Really. That's why you just took Sam's head off for no reason." Dean gave Cas a severe look and the angel ducked his head in shame.

"Dean, I swore to protect you. Both of you. Going to investigate this waypoint is throwing yourselves into danger unnecessarily."

"I feel like I'm repeating myself but we do that all the freaking time. Seriously, Cas, how is this any worse than any of the crazy things we've done over the years?" Dean leaned into the angel's personal space unconsciously and hardly noticed how the angel seemed to lean in towards him too.

"Because Necropolis is more dangerous to your mind than anything you've ever encountered. Yes, you've faced any number of threats to your lives. But this isn't about a physical threat. Necropolis corrupts everyone it touches. Drives them mad. You want to know what I fear more than your death? This is it. You alive but no longer knowing who I am, who Sam is, who you are. No memories, just a shell." Cas was desperate, pleading with him.

Dean frowned at him. "Like uh… earlier this year."

"Exactly," Cas said emphatically, reaching out and grasping the hunter's shoulders. "Dean, I have to accept that one day you will die and I will be left here… alone. But seeing you descend into madness first? I don't know if I can survive that."

Dean looked away, overwhelmed by a surge of emotion. "Don't talk like that."

"I have to," Cas said. "I… I'm scared. Please, Dean, stay here. Let me investigate the waypoint first."

"What, so it's OK for me to deal with you coming back like Arariel did?" Dean said pugnaciously.

"I won't," Cas assured him.

"How can you possibly know that?" Dean growled.

Cas sighed and his shoulders slumped, his hands falling away. "I've been there before."

Dean's jaw dropped open in appalled shock. "What?"

"I've been to Necropolis before. More than once. I can counter its influence."

"I don't understand," Dean said. "Why didn't you mention this before?"

Cas rolled his eyes. "Because I didn't want Gabriel to know."

Utterly baffled now, Dean just gaped at the angel, his mouth opening and closing in astonishment. Cas sighed and raked a hand through his hair. "Were you ever planning on mentioning this?"

"I just did," Cas pointed out ruefully.

"Yeah, because I forced the issue," Dean snapped.

"No, I wasn't going to tell you," Cas admitted. "It didn't seem relevant."

Dean felt like his head was going to explode. "Didn't seem relevant?" he shrieked.

"No. Dean, you're overreacting." Cas said patiently.

"Damn it, Cas!" Dean blew out a breath and got his temper under control. "OK. Why?"

"Because I knew you'd react this way." Cas gave him a slight smile.

"No, why did you have to go to Necropolis?" The smile disappeared.

"I'd really rather not say."

Dean folded his arms and regarded the angel sternly. "Spill."

Cas closed his eyes. "To retrieve the Anima Licio of course."

Too much was happening all at once. Dean's head began to pound. "Is anything you've told us true?"

Cas swallowed. "Not much. Nobody knows except me and uh…" He looked sick. "Michael."

"Michael," Dean repeated, dazed.

"And now, finally, I understand," Gabriel's voice said acidly from behind Dean. "Fucking hell, Castiel."

Cas looked miserable, his face pale and drawn. "I know."

"I'm still confused," Dean confessed.

"The cards," Gabriel said angrily. "None of what we knew made sense. They were just way more powerful than anything a human could create, even one possessed by an archangel."

"You're saying Michael used that loom thing to create the creepy tarot cards of Doom?" Dean said disbelievingly.

"It's the only explanation that explains their power," Gabriel said tiredly.

"Yes," Cas said. "I wasn't sure until I actually saw them in action, but they are the cards Michael made."

"And you were just gonna keep all of this to yourself?" Dean's jaw jutted furiously as he glared at Cas.

"It didn't seem-"

"Relevant? Yeah, you're gonna have to come up with a better excuse than that."

"All right," Cas said. He sounded resigned. "Michael's not in the Cage."

Dean went white. "Is he still possessing Adam?"

Cas shook his head. "I don't know. Michael's been out for at least a year. He contacted me when we were trying to figure out how to battle Amara. He's weak after so long in the Pit. But like it or not, he's still my oldest brother and I owe him my allegiance."

"You're not serious," Dean said.

"I am," Cas said.

"So does this mean he's back in charge in Heaven?" Dean asked.

Cas shook his head. "He's in hiding. Only a few angels know he's out. He's concerned that appearing before the Host in his weakened state would be bad for morale."

"Bullshit," Gabriel said tartly. "It's all about his ego. So, what does Michael being out of the cage have to do with this?"

"Because he knows the cards are active. He doesn't know we have them. I haven't told him." Cas said, shamefaced.

"Look at you, trying to play both sides," Gabriel said. He raised one eyebrow at his brother.

"I'm not… That's not what I was trying to achieve. I don't know for sure what Michael wants the cards for. I was supposed to locate them and hand them over. I agreed to this before Sam got them from Magenta LaCroix. But once I saw them, I realized it wasn't a good idea to give them to Michael. That's it."

"So Michael wants the cards," Sam said, coming around the corner. "And you knew."

"We've been over that part," Dean said. "All right, I guess I understand. But I thought we'd agreed that secrets were bad?"

"Yes," Cas nodded. "You're right. But it wasn't really a secret at first. I just… didn't tell you. Then later, when I should have mentioned it, it seemed too hard to explain. I'm sorry." Dean clapped him on the shoulder.

"Wait, back up a step," Gabriel said. "You entered Necropolis to help Michael make the cards with Ashton LaCroix. I think we need to hear the whole story."

"Fine," Cas said. "I'll explain in the car."

Mary climbed out of bed and padded on bare feet into the bathroom. Ketch rolled over and breathed out steadily. She closed the door and stared at her reflection in the mirror. Sleeping with Ketch had not been smart, even if the man had been an inventive and attentive lover. She quivered at the memory of him slowly taking her apart and then shook her head to dismiss it. She turned on the shower and let the water heat up, jumping in as soon as it was tolerable. She washed with the quick efficiency she'd perfected when on the road with her dad, who had little tolerance for what he called needless fussiness over hygiene. Thoughts of her father brought a sting of tears to her eyes. She wondered what he would have made of all of this. He'd been right about one thing however. A hunter was always a hunter. You couldn't walk away, no matter how hard you tried. And if it was in your blood, like it was in hers, then it was your destiny.

The Men of Letters seemed to have a similar philosophy in many ways. They indoctrinated the kids very young, from what Mick and Ketch had told her. She'd been vaguely disapproving until Ketch had rather pointedly asked her how old she was when she killed her first monster. Since the answer to that question was before her twelfth birthday, she'd grimaced at him and agreed that she was being a little hypocritical.

She climbed out of the shower and dried off on the thin hotel towels. She decided not to bother blow-drying her hair since that might wake Ketch and she'd like to sneak out while he was still asleep. But she was not lucky today, when she opened the bathroom door it was to see him fully dressed and sitting on the edge of the bed, checking his cellphone.

"Good morning," he said chirpily.

"Yeah," she said, not really agreeing but not wanting to make a scene. He quirked an eyebrow at her.

"Going somewhere?"

"I gotta get moving," she said. "Sam texted to say they'll get here in a few hours."

"And you want me long gone before they get here." It was not a question. Thankfully he didn't seem to be offended. "I understand. Let's go get breakfast and then I'll make myself scarce."

His phone buzzed and he looked down at it with a grimace. "Or not. I have to make a call." He dialed a number and held the phone up to his ear.

"Mick, what's up?" Mary tried not to look like she was interested in the conversation but the look on Ketch's face was rather disturbing. "You're not serious!" He exclaimed. "All right, I'll look into it." He hung up and gave Mary an apologetic grin.

"Something's happened."

"You could say that," Ketch said evasively. "It's not related to this case."

"You're sure?" Mary asked.

"Certain. How much do you know about varcolacs?"

Mary couldn't keep her shock off her face and Ketch blinked. "You've heard of them before."

"We killed one a few weeks ago, in Kentucky," she admitted. "We didn't know that's what they were at the time. We only figured it out later."

"They're supposed to be extinct," Ketch snarled. "And they're certainly not supposed to be slaughtering our agents in the field."

"What happened?"

"I don't know," Ketch said in frustration. "All Mick knew was that four agents were killed. One survived long enough to describe what attacked them."

"Where was this?" Mary wondered if she could get a message to the boys before they arrived.

"Florida. Deep in the Everglades. The team were there to track something else, Mick didn't specify. They were ambushed. I have to go immediately and put this thing down."

"It's not going to be easy," Mary said, remembering. "They're tough. I don't know if they have all the features of vampires, but I do know Dean shot the one we killed and it didn't even blink. He had to decapitate it in order to kill it."

Ketch gave her a wolfish grin. "I think I can manage that." He pulled on his jacket and strode towards the door. "I'll be in touch." Mary nodded, not trusting herself to say anything. She wasn't sure if she wanted to see him again or not.

"Come on, Cas," Dean coaxed. "Tell us about your little trip to Necropolis."

Cas shifted in the front seat and made an uncomfortable sound. "It was August 1982. Michael came to me and asked if I was willing to undertake a dangerous mission for Heaven, one I was never supposed to speak about. Of course, I agreed. I didn't know that Anna eavesdropped on the conversation, or that what she learned was part of why she chose to Fall."

"Wait," Dean said, blinking. "Anna knew about this?"

"Not all of it. Just that I was being sent to Necropolis to retrieve the Anima Licio. She disapproved." Cas's mouth drooped. "I guess she was right."

"So what happened?" Sam asked, leaning forward so he could hear.

"I entered the city alone. Michael and I agreed this would be the best way to avoid detection. I was surprised how easy it was to enter and pass unnoticed. I think my human vessel was a good enough disguise." Cas gave a slight smile. "James Novak Sr was an interesting man."

"Jimmy's dad?" Sam guessed and Cas nodded.

"I don't understand," Dean complained. "You and Gabriel said that Heaven sealed off Necropolis centuries ago. So who were you expecting to see there?"

Cas raised his eyebrows. "Nakhte and his followers were sealed inside the city. They've been there ever since."

"They're immortal?"

"No. Time has a different meaning in Necropolis. It's hard to explain." Dean waved him on. "As I mentioned, Necropolis twists and corrupts those who spend any time there. The people who had followed Nakhte into that place were no longer human as you would recognize them." Cas turned to stare out of the window. "Nevertheless, they didn't seem to recognize that I was not one of them. Perhaps the idea of anyone breaking in seemed too unlikely. I found Nakhte in the Fane with the Anima Licio. He was talking to it, and uh…" Cas paused as he grasped for the right word. "Petting it. It was a disturbing sight. He attacked me as soon as he heard me enter and we fought. I was injured but not severely and managed to make my escape with the Loom."

"So how did you resist Necropolis's influence?" Gabriel asked thinly.

"Michael believed that entering in my True Vessel offered some protection. And he linked our Graces together, providing me with a tether back to Heaven."

"Castiel!" Gabriel gasped, scandalized. Sam leaned back and stared at him, before meeting Dean's eyes in the rear-view mirror and shrugging his confusion.

"What's the problem?" Dean snapped.

"It's OK," Cas said. "Gabriel's right. What we did was forbidden. But it worked. My mind and Grace were unaffected by Necropolis's evil effects."

"Do I want to know why it is forbidden?" Dean sighed.

"Because it can be hard to separate the two angels once it's done," Gabriel snarled. "When Lucifer Fell, he took many of his followers with him because he'd linked his Grace with theirs. Angels who might have been redeemed were doomed to Fall. We tried to save them all but the link was too strong."

"So are you still linked to Michael then?" Dean asked. "How come he didn't drag you into the Cage?"

"No, the link was broken," Cas explained. He blinked rapidly and for a moment Sam was sure he might begin to cry. "By you."

"What?" Dean yanked the steering wheel over to the right and pulled the car onto the verge.

"When we met, in Hell, your soul wrapped around my Grace so tightly, you pushed everything else out. Including that link to Michael." Cas gazed earnestly at Dean, who couldn't look away. "It was incredible, I couldn't believe it was happening but you were insistent on stripping away anything that wasn't you or me."

Gabriel whistled in surprise, his eyes looking suspiciously moist. "That shouldn't have worked, you know," he commented.

"But it did," Cas asserted.

"I wonder why." Gabriel looked troubled now and Sam resisted the urge to reach out and touch him. "Perhaps because Dean is Michael's True Vessel?"

"That could make sense," Sam agreed. "But however it happened, doesn't this mean you wouldn't be protected if you entered Necropolis again?"

The angel frowned. "I hadn't considered it."

Dean thrust both of his hands into his hair in frustration. "So we're back at square one! It's no safer for you to go than any of us. Damn it, Cas."

"I'm sorry," the angel said miserably. "I was only trying to protect you."

"Well don't," Dean snapped. "I'm a big boy. I can take care of myself."

"Of course," Cas agreed meekly. But his eyes still flashed with defiance and Sam knew there'd be more trouble ahead.

Mary heard the distinctive throaty roar of the Impala as it pulled into the parking lot and got up to meet her boys. She was immediately aware of the tension between Dean and Castiel that suggested they'd been fighting. And to her disapproval, that Gabriel character was still hanging around too. Yes, she'd been grateful to him for what he'd done for Sam on Vancouver Island, but that didn't mean she trusted him.

"Sam, Dean," she said warmly, enfolding them both in a hug. She shook Cas's hand and then nodded politely to Gabriel. He seemed distracted and didn't notice her rudeness but Sam took on a pinched expression and his nostrils flared. She ignored it.

"I hope you're up for a hike," she said. "The trail is long and quite rough."

"We'll manage," Dean said. "How far is it?"

"It's a couple hours," she admitted. "We have plenty time to catch up. I can tell you what I found in Chicago and then you can explain what this business with the tarot cards is all about."

Dean nodded and they all listened as Mary led the out to the trail and began telling them about what she had found out about Constance McBride's activities. When she got to the Banes's speculation about nephilim and how that might tie into the midwifery course she was pursuing, Dean stopped her and pulled a face.

"You don't really take this idea seriously, do you?" he asked, looking vaguely nauseous.

"I don't know what to think," Mary told him. "If she needed an excuse to be near whatever the Hell it is I found behind that waterfall, nursing school really doesn't cut it. There are any number of ruses she could have used. So I have to think the courses are not just for show. Especially since she is not only showing up but getting good grades."

"Even if the nephilim theory is wrong, I think Max and Alicia are onto something," Sam commented. "If she's using human women for breeding purposes-" he paused as his gorge rose at the thought.

"All of Heaven would be in uproar if she were breeding nephilim," Cas rumbled. "We all hear it when one is created."

"Even in Necropolis?" Sam asked. Cas and Gabriel frowned at each other.

"I don't know," Cas said finally.

"Me either," Gabriel agreed. "It's not like we tested it out or anything."

"I'm not sure it matters," Mary interjected. "I think the breeding program part might be right." She pulled out piece of paper and handed it to Dean. "These are missing persons statistics on women of child-bearing age in Illinois. See how the numbers are really stable until last year when they increased over 400%!"

"How come this hasn't made the news?" Dean wondered.

Mary gave a soft sigh. "Because most of these women didn't have families or lots of friends making a fuss, as far as I can tell. And it's just diffuse enough across the state that nobody noticed, I guess. I had a real hard time even getting these numbers and the journalist who gave them to me wasn't sure how solid they were."

"I wonder if there are missing women from other states as well," Sam mused. "Especially those that have an Illinois border."

"It's possible," Mary agreed. "But getting the statistics is shockingly hard."

They had just turned a corner in the trail and a couple of hikers were coming the other way, breathing hard and sweat beading their faces. Mary smiled at them and they frowned.

"Today's not a good day to visit the falls," the man said, his bearded face drawn with concern.

"Oh?" Sam said.

The two hikers looked at each other and the woman nodded to her companion. "The light is just really bad in there today."

Certain there was something more to this, Sam shrugged. "Maybe the sun will come out later."

The couple exchanged another look. Eventually, the woman said, "Look, it's up to you. But we just got a really bad vibe out there, OK?" Without another word, they began walking again.

"Bad vibes," Dean repeated. "Awesome."

The waterfall was as lovely today as it had been when Mary had visited it with Ketch yesterday, and yet as the other hikers had reported, it did seem strangely gloomy even when the sun peeked out from behind the clouds. A shiver passed through her and she saw Sam and Dean do the same. Cas and Gabriel looked distinctly nervous and that made her antsy too.

"So, you said it was behind the waterfall?" Sam said doubtfully.

"Yeah," she said, pointing to the path that was almost completely hidden by bushes. "It's back here." They all followed her along the path behind the falls, sliding on wet rock and, in Dean's case, swearing under his breath.

The thrumming sound Mary had noticed yesterday was much louder today. It thudded against her skull like a migraine, making her feel dizzy and uncomfortable.

"What is that sound?" Sam groaned, pinching the bridge of his nose.

"I don't know," Mary said. "We heard it yesterday."

Dean's head whipped around like a snake. "We?"

"I wasn't the only person here," Mary said defensively, internally cursing her loose tongue. "There were other hikers too. Anyway, here are the carvings I found."

Gabriel and Cas both gasped. "This is no waypoint," Gabriel asserted. "It's the Gate."

"The Illini Gate," Cas agreed. "This must be where Arariel passed through into Necropolis."

"I wonder how he opened it," Gabriel mused, looking around for any other carvings. "There's no opening rune that I can see."

"It might be hidden," Cas said. "When I passed through the Kemet Gate, it was concealed behind a powerful glamor that my Grace couldn't penetrate. Michael was the only one who could see it."

"Hmm," Gabriel said, wandering away from the carvings and squinting at the rock walls. "With my Grace locked away, I don't know if I'll be able to find it."

"We're not gonna open this Gate are we?" Dean demanded.

"No," Gabriel said absently as he poked at a spot close to the floor. "I just wanted to know who had opened the Gate for Arariel. The list of suspects is not long but if we find the opening rune, we might be able to detect Luci's Grace, or Dagon's corruption or whatever."

"Is there a spell we can do that might help?" Mary asked.

"I don't think so," Cas replied. "Anything that can mask itself from my Grace is way to powerful to be revealed by witchcraft."

As the conversation continued behind him, Sam drifted closer to the carvings. His feet seemed almost to be dragging him there without his consciously deciding to move, until he was almost touching the symbols. They seemed to dance in front of his eyes, a twisting, sinuous movement that called to him on some primitive level. In a trance-like state, he lifted his hand to trace the shapes and felt the tantalizing thrill of power just below the surface as he did. He'd almost completed the last rune when the sound of Gabriel's shocked voice penetrated the fog in his head.

"Sam! No!"

But whatever Gabriel had been attempting to prevent had already been set in motion. The headache-inducing thrumming sound got louder and more insistent and Sam realized that the carvings were glowing softly. And then they began to rotate around a central point which seemed to be receding into impossible distance until all Sam could see was a swirling gray-blackness that gaped in front of his eyes and he yearned for it. Without thinking, Sam tried to step forward, and only then did he realized that Dean, his mom and both angels were holding his arms and attempting to drag him away. He shook them off easily and leaped forward, unable to resist the siren song of the abyss. He felt something tug at his jacket and then everything went black.