Vivienne watched Leonard fall to the floor with disbelieving eyes. "Really?" She asked his prone form.

Penny couldn't stifle her little giggle. "It's the blood," Sheldon offered from his place beside Penny.

Peter raised his weapon, and pressed the trigger. Nothing happened. "Fucking eBay," Peter snarled. They heard Howard and Raj coming up the stairs. Sheldon darted to his room. Penny stood and stared wide-eyed after him.

Vivienne grinned like a shark and took a step towards Penny. "You started all this, didn't you?"

"This is in no way Penny's fault. Step back from her," Sheldon's voice said firmly from the hallway. They all turned to face him, to see him holding a crossbow on Vivienne.

"Got wood, Sheldon?" Vivienne asked, indicating his arrows.

Sheldon hesitated, and Penny hauled off and punched Vivienne. The next couple of minutes were chaotic, but ended with Penny straddling Vivienne, a stake, grabbed from Charley, poised above her heart. Vivienne suddenly had a lot more teeth, but inexplicably hesitated to attack Penny.

Penny, noticing the hesitation, hesitated in turn. "Where do you get your blood?" Penny asked suddenly.

Vivienne's teeth went back to normal. "I have a friend who works in a hospital, he gets me…." She trailed off.

"Can you release the boys?"

"They'll be released when you stake me," Vivienne said sullenly.

"Is that the only way they can be released?"

"No," Vivienne said with sudden hope.

"Penny," Sheldon said urgently.

"I know, Sweetie, but, what if she's not eating people? Is it right to…?" She gestured with the stake.

"Your contention being that she may be a monster without being monstrous?"

"Peter, is it possible?" Penny looked to the door, where Peter stood nonchalantly leaning against the wall, clearly enjoying the two attractive women scrapping.

"I've certainly never heard of any such creature, but, there are more things in heaven and Earth…." He finished with a shrug. "The question is, love, are you prepared to risk it?"

"Is there a way to un-invite her from Sheldon's place?" Penny countered as moved the stake away from the vampire beneath her. Vivienne remained passive, hopeful for the first time in a hundred years.

"Yeah," Peter said. "There's a way."

"You don't eat humans?" Penny asked Vivienne to be certain.

"Why is Penny sitting on Vivienne?" Leonard asked as he sat up. "Are they fighting?" The "over me," was implied by his smug grin.

"No, I don't, Penny. Not for a long time. Too much blood already." Vivienne's voice was raw. The same instinct that told Penny that Vivienne had been acting a part earlier, told her that Vivienne was being honest now. Penny had no trouble believing her.

"And you'll release the boys?"

"Yes," Vivienne replied.

Penny stood up and offered a hand up. Vivienne raised her eyebrows in surprise as she accepted it.

"Why?" Vivienne asked finally.

"Why didn't you attack me?" Penny returned.

"Someone wanna' catch me up here?" Leonard asked querulously. He was ignored.

"I've seen so much bloodshed already, I just…." She gave an eloquent shrug.

"I wouldn't have thought you could resist." Amy said, with an odd note in her voice.

Charley, clearly remembering that Amy had attempted to bite him, gave her hand a reassuring squeeze.

"A hundred years ago, no I couldn't have. But the older I got, the easier it got to ignore the need for…. I still need blood, but I don't have to hunt for it. Not anymore."

"Oh."

Leonard had been ignored long enough. "Okay, what the hell is going on here. Blood? And what's up with Howard and Raj?"

"Really, Leonard, I would have thought it would be evident to even someone of your intelligence." Sheldon started. Penny glanced fondly at him, and he caught her gaze, and felt the heat rise in his cheeks. "Vivienne is a vampire, and has enthralled Wolowitz and Koothrappali. Peter Vincent and his merry band of vampire hunters came to help us destroy said vampire, but Penny has realized that it is unnecessary. And now Vivienne is going to release Wolowitz and Koothrappali."

"What?" Was all that Leonard could manage.

Sheldon sighed, turned to Penny with a look that said: "do you see the lesser minds that I am forced to deal with?" Penny grinned at him.

"Vivienne, would you please?" Penny gestured at the boys.

"Oh, of course." Vivienne looked into each Raj's eyes and released him, and then did the same for Howard.

Both men blinked rapidly, and looked around them in confusion. "What's…hey, I think there's something wrong with…arg!" Howard broke off as he caught sight of Sheldon's crossbow. "Has he finally snapped?"

Peter actually was the one to answer. "If what I've seen thus far is any indication, he's the only one of you who hasn't."

Howard looked at him in surprise. "You're Peter Vincent."

"I was aware of that, thanks."

"Hey, man, no need to be…."

Penny cut him off. "Peter came to help, what do you remember?"

"Going to Vivienne's apartment and… oh my God." Howard turned bug eyes towards Vivienne. "You're a vampire!"

Taking a page from Peter's book, she replied, "I was aware of that, thanks."

"Sheldon, shoot her!" Howard cried.

"I'll do no such thing. She released you in good faith. Penny, who has a much better grasp of these things, has accepted her word that she does not hunt."

"And you're going to trust a vampire?" Leonard demanded in a whiny voice.

"No," Sheldon said firmly. "I trust Penny." There was something in Sheldon's voice that silenced Leonard.

Howard turned hopefully to Peter. "Can you use that thing?" He pointed to his stake-gun.

"Nah, jammed."

Howard stood there jabbering for a few seconds and looking wildly around the room. Raj slapped him across the face. "Dude, calm down."

"Sheldon hates us now, why would you think that we're safe?" Howard asked harshly.

"Because Sheldon isn't like that," Penny said. "Isn't like you guys. It would never occur to him to do such a thing."

"You think we'd let …?" Leonard trailed off in shock.

"I think you're capable of a lot worse things than I ever would have believed three months ago." Penny replied bluntly.

"What are you talking about?" Vivienne asked curiously.

"They were on an expedition…," Penny started.

"Oh, to the Arctic, no?" At Penny's nod, Vivienne continued. "And something unfortunate happened?"

"Yeah, Sheldon was a ginormous dick." Howard said.

"And these guys screwed up the test results." Penny finished.

"Doesn't it make you all look bad to have false results on a project?" Charley asked, shocked.

"Meh, it was Sheldon's project." Howard said.

"Why did you two save these arseholes?" Peter asked.

"Because it was the right thing to do." Penny said for both of them. Sheldon merely nodded. He'd actually managed not to think about the betrayal for a few days.

"You're a better man than I am, mate." Peter said.

"We like you, anyway, Pete," Charley said with a grin and Amy nudged Pete's shoulder with her own.

Peter smirked at them and draped an arm over each of their shoulders. "Are we ready to un-invite Vivienne from the apartment?"

"Can I ask you something first?" Penny asked Vivienne.

"May you," Sheldon murmured.

"May I?" Penny corrected after rolling her eyes at Sheldon.

"Of course," Vivienne answered.

"How do you look so cute when you can't see yourself in a mirror?"

"I'm one hundred and twenty-four years old. I'm quite familiar with where things are on my face." She smiled as she said it.

"Oh, like Sheldon's imaginary whiteboard."

"Very good, Penny. There may be hope for you yet," Sheldon teased.

She narrowed her eyes at him, and he took a step back, before she smiled at him.

"Hey, Peter?"

Pete nodded at Penny in acknowledgement.

"How come her clothes don't show up either?"

"Ah, that's actually very interesting," Peter, who had made a study of vampires, said. He then went into a long a complicated explanation, made harder to comprehend due to his thickening accent as he got into his explanation.

When he finished, Penny turned blank eyes to Sheldon, who said, "Proximity."

"Oh," Penny said in comprehension. She turned to Pete. "Thanks," with a sunny smile.

"You're welcome?" Pete replied. He said to Vivienne, "I'm ready to do the un-invite. You want to step out?" And he commenced digging into his bag.

The un-invite was relatively easy, and took about fifteen minutes to complete. Afterwards they all trooped down the stairs, where Vivienne was waiting to say good-bye.

Penny stood next to Sheldon, their arms brushing gently. Vivienne stood a few feet away from Penny, and Leonard, Raj and Howard stood on the other side of the Vegas contingent, as far from Vivienne as they could.

"Thank you," Penny said. She hugged each of the vampire hunters. "Really, thank you for coming. Please come and visit any time you're near. We'd love to see you all again."

"We're glad that slayage was unnecessary." Pete nodded at Vivienne.

"Me, too," Vivienne echoed, with a smile. "Goodbye."

Peter looked around, rested a hand on the shoulder of Charley and Amy, and said, "I think it's time we headed on home, kids."

With a last wave, they left. Penny and Sheldon turned to go back upstairs, but Penny stopped abruptly. "The cameras."

"Of course," Sheldon agreed. He turned to Vivienne. "May I enter your apartment to remove the cameras that we placed?"

"Cameras!" Vivienne exclaimed.

"Yes." He answered briefly and then stared at her awaiting a response to his question.

"By all means, please remove them." She gestured towards her apartment. Sheldon hesitated before crossing the threshold and then felt Penny at his side. She gave his hand a quick squeeze, before releasing it. She stood on the doorstep, between Sheldon and Vivienne.

Penny awkwardly bit her lip, "I couldn't help noticing, Vivienne, you have the cutest pair of Louboutins."

"The blue ones?" Vivienne returned with a smile, choosing to ignore that Penny had clearly seen them while snooping through her apartment.

"Yeah," Penny agreed eagerly. "Where did you find them?"

The women spent the few minutes that it took Sheldon to remove the cameras, talking about shoes. They trailed off when he returned to the hall.

"I'm not sure that thanks are appropriate, but, thank you," Vivienne said, finally.

"You should be thanking us," Leonard blustered, clearly feeling that he had been ignored long enough. "You were going to…."

"I was trying to lay low, you were the one who kept coming back, and stealing my mail," she said with a shudder.

Sheldon and Penny exchanged a look.

"I-It was mis-delivered."

"That happens a lot around her," Penny offered. "Ignore it."

"It will certainly cease when Leonard moves out of my apartment." Sheldon said.

"When I what…?" Leonard sounded shocked.

"You imagined that I would permit you to stay after you betrayed me, science and our friendship? As little as I think of your intelligence, I thought you smarter than that."

"Bu-but, we're friends." Leonard protested. He never would have thought Sheldon could forgo his routine.

"I am reliably informed that we are not; that friends do not under any circumstances do what the three of you did. And whilst I will not be pursuing this matter through Caltech, merely reporting the expedition a failure," Sheldon's lip curled as if the very word was distasteful to him, "I will not be content with you in my personal life. I would not know what betrayal might next come."

"You want to talk about betrayal?" Leonard said hotly. "What about you and Penny, huh? She was mine."

"Yours?" Penny said in surprise.

"Uh, oh," Howard said. Raj, having gotten over his shock and remembering that he couldn't talk in front of women, merely nodded.

"Well, yeah, kinda'. I saw you first and talked to you. I had dibs."

Penny's face was a mask of rage. "Dibs? Who the hell do you think you are?" She stepped towards Leonard, mayhem written all over her frame. "You obnoxious, whiny, little prick…." She would have continued in this vein, had she not caught sight of the anxiety on Sheldon's face. She raised her eyebrows in question.

"Please don't fight, Penny." He said in a small voice.

Penny deflated, shot Leonard a venomous look and said, "I'm sorry, Sweetie. He's not worth it anyway. Let's go back upstairs, and watch a movie while Leonard packs, okay?"

Sheldon smiled sweetly at her. "Thank you, Penny." And followed obediently after her. Once upstairs, Sheldon grabbed a couple of movies he thought Penny might like, based on her interest in "Iron Man", Peter's faulty stake-gun, which he'd left on the floor and returned to Penny.

Downstairs, the other three guys stood and stared at each other, then turned as one to look at Vivienne. "Don't look at me; I don't want to have anything to do with you, either." And she went into her apartment and firmly closed the door. They heard the lock click into place.

It actually took Leonard all weekend to get all of his things out of the apartment, and Sheldon spent that time at Penny's. Turns out she really liked "Thor" and thought Loki was awesome (she didn't mention that he reminded her of Sheldon).

Leonard ended up having to store most of his stuff, and stay on Howard's couch. They couldn't really hang out at Howard's, because his Mom was really loud. They tried to hang out at Raj's, but it was kind of small.

Sheldon was dreading having to look for another roommate, when it occurred to him that he and Penny had cohabitated quite well. He worked at his board feverishly, trying to work out mathematically whether he and Penny could coexist. In the end, it was the realization that he wouldn't really trust anyone else in his space that made him suggest it to her.

Penny considered long and hard, tried to be logical and weigh the pros and cons, and finally decided that it was a practical and logical solution to her always-present financial woes as well as persistent loneliness that drove her to sometimes bring men home.

They trundled along happily, Sheldon getting increasingly more willing to be touched, and occasionally touching her if the situation warranted it. As the months went slowly by, fall sliding into winter, Penny got a few acting gigs, which made her happy.

Sheldon had taken apart Peter's stake-gun, reassembled it better and mailed it back to Peter. Peter was quite pleased with how well it worked, and asked Sheldon if he could send him something else he'd bought that didn't work properly. Sheldon agreed to look at the item. They went back and forth with weaponry in this fashion, Sheldon honestly dismayed at how much stuff Peter bought that didn't work as it should.

Penny and Vivienne hung out sometimes, at Vivienne's place, and often went clubbing together. Vivienne had to be careful, because her reflection didn't show up, but Penny was a surprisingly quick-witted ally. They also shoe shopped, online, as Vivienne had found some really awesome bargain sites. Sheldon, in the privacy of his own mind, heaved a sigh of relief that he would not be expected to listen to Penny talk of shoes.

On their way out to a club one evening, the two women ran into Leonard coming to pick up something he'd "accidentally" forgotten. He froze at the sight of Vivienne, and then looked confused as to what she and Penny would be doing together.

Neither woman acknowledged him, but being Leonard, he forced the issue. "Where are you two headed," he asked.

"Not that it's any of your business, but to a club," Penny answered.

"Are you sure it's safe, Penny?" He asked with a nervous look at Vivienne.

"I'm sure I'm safe." She barely emphasized the second "I'm".

Leonard turned to Vivienne, "you'd better not hurt her." He tried to sound threatening.

In a blur Vivienne was in his face with all of her teeth bared. Leonard yelped and tried to step back. With a huff of laughter, she glanced down at his crotch; he had wet himself.

"My hero," Penny said. Leonard didn't need a sarcasm sign to know she didn't mean it. The two women went on their way without a backward glance.

Leonard tried to wheedle his way back into Sheldon's good graces (and more importantly into the comfy apartment), trying to convince him that Howard had been the ringleader. Sheldon was singularly unimpressed with this, and dismissed him.

Howard had bragged about the "prank" the guys pulled on Sheldon, although only the three of them seemed to find it funny. Nothing was ever officially said, so they blithely thought they were free and clear. Until the bill showed up for the fraudulent experiment. All charges from the Arctic expedition, including Sheldon's salary, were being billed to Leonard, Howard and Raj by the NSF. Leonard took it to Dr. Seibert, who looked over his glasses at him, and asked him what he had expected.

Tails between their legs, the guys set up payment arrangements.

More time passed and Sheldon became less and less satisfied with Caltech. On a dreary winter day, Sheldon's phone rang. "Hey, there mate." Peter's voice was cheerful. "How would you and the lovely Penny like to come to Vegas for a visit? We've got a situation and really could use your help."

A/N "…may be a monster without being monstrous" Borrowed with generous permission from ConeycatJr