Dean put down the newspaper he was pretending to read and pulled out his phone. He dialed Sam, never taking his eyes off the guy at the table in the back corner. The guy was pale, with black curls and a face that had practically made the waitress swoon. He was sitting alone, a pot of tea and a cup on the table in front of him, and he was quite clearly flirting with the empty space across the table from him.

Sam picked up after three rings. "I'm in the library, Dean, this better be important."

Dean kept his voice low. "You know that weirdo we walked past on the way to the library? The one who was talking to himself? Leather jacket, fingerless gloves?"

"He's not our guy, Dean. He's just a regulation crazy."

The waitress arrived at the guy's table with a plate of meatloaf and a flirtatious smile. Curls smiled back politely and thanked her. "Ooh, you're IRISH," the waitress practically squealed. "I love an Irish accent. I get off at 3. Call me." She handed him a napkin, presumably with her number on it. Irish glanced uncomfortably across at the empty space before handing the napkin back, shaking his head.

Interesting.

"Sam, he's not talking to himself," Dean insisted. "There's someone with him. Someone… invisible…" He trailed off.

"Dean?" Sam's voice came through the phone, "Are you still there? I mean, I guess it could be, we've come across it before. But what makes you think there's someone there? He seemed like he was just talking to the air this morning."

"Dude," Dean hissed, "His tea just poured itself."

Mr Irish dreamboat was leaning across the table, whispering something to the empty space and indicating to the teapot. Probably reminding the empty space not to pour his tea for him in public. Kind of hypocritical, Dean thought, considering how completely unsubtle the guy was about talking to the tea-pouring empty space.

"I'm on my way," Sam said, rustling papers as he hurriedly gathered up his research, "Keep him in sight, I'll be there in five."

Dean put his phone back in his pocket and sipped his coffee. Black and bitter, and almost undrinkable, but at least it wasn't tea. He picked up his paper and went back to pretending to read the sports section. Irish was looking in his direction, all traces of the happy grin he'd been directing at the empty space gone. His face was planes and hollows and shadows, and he looked dangerous. He stood up and stalked towards Dean.

Dean pulled his gun out of his waistband and held it cocked under the table. It never hurt to be prepared.

Irish leaned over Dean's table, eyes dark with fury. Dean kept his fingers relaxed on his gun. Accidentally tightening his finger on the trigger when it was that close to his own private parts would not end well.

"Why are you watching me?" Irish growled.

Dean said the only thing he could think of that would be believable. He mustered up the flirty smile that rarely saw the light of day these days and said, "I was just wondering what a handsome devil like you was doing all alone."

Irish relaxed, letting out a little chuckle and raising his eyebrows. "The same could be said for you. I'm waiting for my friends. They should be here soon. You?"

Huh. He hadn't been expecting that. He was almost sure the guy was flirting with him, although that could just be the accent. "My brother's on his way. I'm Dean." He held his hand out to shake. If the guy was something supernatural, he might feel something with skin to skin contact.

Irish grasped his hand. Dean almost flinched at the cold. "Mitchell," Irish said, "Sorry to tell you this Dean, but you're too late. I've got a girl now."

Dean didn't miss the look Mitchell cast towards the empty space at his table. There was pure adoration in that look. He found himself almost wishing someone was looking at him that way, although not necessarily a curly-haired Irishman with weirdly (maybe supernaturally) cold hands.

"Oh," Dean said, awkwardly. "Well, sorry for interrupting your lunch."

"Don't worry about it, man," Mitchell told him, clapping him on the shoulder and sending a jolt of cold through Dean's three layers of shirts. "You gotta put yourself out there. That's what being human's all about."

Dean watched him as he went back to his table and said something softly to his empty space, reaching across to stroke the air at head height, like someone cupping his girlfriend's cheek.

A moment later, two more people joined the party, taking the seats on either side of the table, leaving the one opposite Mitchell empty. The new arrivals were clearly a couple. The guy wore glasses and had some serious ears, while the woman was small, blonde and businesslike. Both of them greeted both Mitchell and the empty space. The new guy said something Dean couldn't make out and clapped the empty space on what was probably the shoulder.

This was definitely not just a crazy guy. There were four people at that table, but only three were visible.

Dean made his coffee last until Sam arrived. When Sam had sat down and ordered, Dean nodded towards the table. "What do you see?"

Sam frowned at him, "Three tourists having lunch."

"Okay, two things wrong with that sentence," Dean said, "First of all: tourists? Here? And second, there are definitely four of them. And that Mitchell guy's hands are way too cold to be human."

"There are three people at that table, Dean. Two men and a woman. And how do you know his name? And what his hands feel like?"

"He saw me watching and came over and introduced himself," Dean admitted shamefacedly.

Sam frowned, "If he caught you watching him, he must be pretty alert. He could be watching for hunters. But then again, he could just be a normal guy with poor circulation who feels weird about having a random guy staring at him while he's trying to eat. You've got no proof he's not human – oh, no way!"

The teapot had once again lifted itself off Mitchell's table and was pouring steaming brown liquid into the cup in front of glasses-guy. Glasses-guy batted it away, saying in a voice loud enough to carry to Sam and Dean's table, "You can't pour us tea in public, Annie! No-one knows you're there! They'll think the teapot is moving by itself!"

This exclamation was met with a chorus of "Shut up, George," from the others at his table, followed by worried glances around the diner to check nobody had heard.

Everybody had. The rest of the people in the diner were frozen, staring at George and the floating teapot.

"I think it might be time for a rest, dear," The blonde woman said to George in a brisk, nurse-like fashion, "Why don't we take you back to the hospital?"

Most of the customers turned back to their food politely, obviously not wanting to stare rudely at the poor man on his day out of the hospital, and somehow explaining the teapot away as imagination or a trick of the light.

The teapot dropped to the table with a dull thud, tea spilling in a pool over the surface of the table and running over the edge in a small waterfall. The empty chair opposite Mitchell was shoved backwards.

Mitchell stood up, holding his hands out placatingly. "Annie," he said softly, "Oh, Annie, it's ok, c'mere..." He rounded the table and held his hand out to the empty space, before turning and walking out of the diner like he was holding hands with someone.

George made to follow him, but the blonde woman tugged him back into his seat. "Give them a minute."

George clutched his head in his hands and groaned. "I am not moving again."

"Okay, you're right," Sam admitted, "There's definitely an invisible woman in town."

"But she's not invisible," Dean said.

"What do you mean?" Sam asked.

"Well, that Mitchell guy can clearly see her, and it seemed like George and the blonde chick could too. Come on," He pulled out his wallet and tossed some cash on the table. "Let's go see what Mitch and his invisible girl are up to."

Mitchell and the invisible girl were down the side alley by the bins, hugging. Dean and Sam poked their heads into the alley, watching as Mitchell rubbed the empty space's back and kissed her on the cheek, murmuring comforting words.

"Do you think?" Dean asked.

"She doesn't seem to like being invisible," Sam said, "If she gets angry about it, she could probably do a ton of damage. I'll head back to the library, you keep an eye on them."

Dean stayed where he was, peering around the corner and watching as Mitchell and the invisible girl sat down and leaned against the alley wall to have a conversation. He felt like a bit of a dick for intruding on their private moment, but he couldn't afford to let them out of his sight, considering one of them was invisible and one of them was probably not human. He had a feeling if Mitchell gave him the slip, he'd be pretty hard to find again.

"He-hem!" Someone cleared their throat behind him. He turned to see glasses-wearing George standing behind him, the small, businesslike woman beside him. Suddenly, glasses-wearing George didn't seem quite so bumbling and awkward. His arms were folded across his chest and he wore an expression of stone-cold displeasure. His girlfriend mimicked his stance. Dean had a feeling she wasn't one to put up with any nonsense.

"What are you doing?" The woman asked, in a tone that suggested she would see through any lies immediately.

He put his hands up in a gesture of surrender. "Look, we just want to help."

"And how could you help us? We will not be coming to your research facility, thank you," George did air quotes around the words "research facility", reminding Dean so forcibly of Cas he almost laughed.

"We don't have a research facility," Dean told them, "I mean, Sam's at the library, and we do have a batcave now, but… anyway, we're not evil scientists or anything. It's just we've come across an invisible guy before and helped him become visible again."

"Like I said," said George, "We will not be accompanying you to your research facility. There's no cure and none of us feel like exploding today."

The air beside Dean got very cold suddenly. He turned to look and found Mitchell standing there, his arm around the empty space. Huh. Silent feet. The Irish dreamboat with the invisible girlfriend and extremely cold hands was suddenly looking even more suspicious. Dean became very aware that a) he was surrounded and b) George had included himself and his girlfriend amongst those who would object to having supernatural research conducted on them.

The frigid air moved beside him, making a sound almost like words. Dean updated his diagnosis from invisible woman to spirit, although that didn't explain why she could be seen by the other three.

Mitchell sighed. "Fine," he said to the cold air, and then to Dean, "Annie wants to know how you made the other guy visible."

"You didn't by any chance make a wish in a magic wishing well, did you?" Dean asked without much hope.

"Why the hell would we wish for this?"

Dean looked at the place where he thought Annie was. Maybe speaking directly to her would help. "Annie? Are you a spirit? We can help you cross over."

The next thing he knew, his back was against cold brick and Mitchell's hands were balled in his shirt, fists digging into his chest. "Who are you? Did they send you?" Mitchell's voice was low and dangerous, his face very close to Dean's. "We don't need your help. She's not going back there."

Oh crap. This was like the zombie college chick situation all over again. He'd tried to bring his girlfriend back from the dead and she hadn't quite made it. It wasn't like he had any grounds to preach about the dangers of bringing people back from the dead, but at least he could say he was familiar with the problems involved.

"Did you make a deal? How long do you have? Or was it a spell? Look, man, these things always turn bad. Trust me, I know." It was probably a spell, to be honest. Spells were usually the way to go when you wanted someone to get stuck halfway. "She'll stay here, stuck, and she'll get lonely and frustrated and angry and she won't be the same Annie you knew when she was alive. She'll turn vengeful."

Mitchell growled at him, a low animalistic sound that reminded him of the hellhounds building up for the chase. A small thrill of fear ran through him. "She doesn't want to go through the door. She was forced through and made to wait, lonely and scared, against her will. She wants to be here with me and George and Nina, and if you try to hurt her I will kill you."

"So will I," added George.

Nina just glared at Dean. She and George had crowded in closer, but whether it was in preparation to aid in Dean's death or to pull Mitchell off was unclear.

"Do you understand?" Mitchell's eyes flashed black for a second.

Shit.

Dean reached for his knife. "Christo."

The Irishman's eyes went black again and he stepped back like he'd been burned. "Christo," Dean said again, watching as Mitchell flinched, snarling.

But then George stepped between them. "Stop. If you hurt my friend, you have me to deal with. I am much more dangerous than I look. Particularly on a full moon."

Dean stopped. Seriously? A werewolf? One claiming to be friends with a demon who had a ghost for a girlfriend. He looked at Nina. "What are you, a vampire?"

She frowned at him. "No, Mitchell's the vampire. I'm a werewolf."

Dean gripped his knife tightly, calculating the odds. Two werewolves, currently not furry. He could deal with them easy enough, but these days they tried not to kill werewolves without proof that it was out of control and they were killing people. One Vamp, unpredictable because he was some kind of new breed Dean had never encountered before. And one ghost. Dean could feel her glaring invisibly at him from the cold spot between him and Mitchell. He raised his hands. "Ok, I'm putting the knife down."

"You do that," said Mitchell, looking recovered from the invocation of Christ.

"That's better," said George after Dean had placed the knife on the ground, "We don't like hurting people. Well, Mitchell kind of does, but he's trying really hard not to and he hasn't killed anyone for ages. He feels really guilty about everything too –"

"Not helping, George," Mitchell interrupted.

"Well, anyway," George continued, "We're not here to hurt anyone. We're just a group of people with unusual conditions that we have under control. All we want in a normal life. Just four normal people, minding their own business. I mean, all Annie was doing was pouring tea and you had to come in all nosy and assume you know best because what? You go around sending people through the door? I bet half of them didn't want to be shoved through and are over there, sitting miserably in purgatory because you didn't bother to ask. I mean, look at Annie. She was dragged through, kicking and screaming, and she was terrified and unhappy there until Mitchell went through and got her back. And now she's back and it's better for everyone. The nerve of you, saying she's going to turn vengeful. For your information, she's already had her revenge, and now she just wants to be here with us."

"She didn't seem that happy before," Dean said, because he had quite definitely seen an upset ghost storming out of a diner to be comforted by her vampire boyfriend not fifteen minutes earlier.

"She misses other people sometimes, it doesn't mean she wants to go through the door," Mitchell glared at him. "But we're working on it, aren't we Annie," he smiled at the space where Annie stood, his whole demeanor changing as he looked at her. "She was corporeal for a while. Even worked in a pub. Maybe one day she will be again. But we don't need your help. We've had enough of self-righteous, vengeful humans on holy missions, thanks. Now get out of here."

Dean moved to pick up his knife, but George shook his head slowly. He left the knife and made his way out of the alleyway, shivering as he brushed past the cold spot.

"How'd it go?" asked Sam when they met back at the car.

"Not well," Dean replied, and told him about the strange group.

"I found a spell to make a spirit corporeal," Sam said.

"Yeah, they seemed pretty adamant about not wanting help from interfering humans," Dean replied.

"Well, it's here just in case," Sam folded himself into the passenger seat, "Do you think they're our killers?"

"Maybe," said Dean, starting the engine. "That George guy was pretty insistent that none of them were killing, but they could be covering for each other. And if it's Annie pushing all those people down the stairs, they'll definitely be protecting her, and maybe even hurting people trying to stop her. That Vamp Mitchell, he loves her. He crossed over to bring her back. He'd definitely attack anyone he saw as a danger to her. And George, he's much tougher than he looks, and he cares about her too, and by the looks of things he'd cover up for the Vamp as well. And his girlfriend looks like she'd deal with a situation she saw as a threat pretty easily."

"We should look into them then," Sam commented, "At least we know their names now. We can check into them and see if any of them has a reason to shove young men down the stairs."