A/N: I'm not sure if I like this, but I wrote it in two hours. I wanted to write something for Halloween but I just got my laptop back two days ago. I've been writing a little bit of Plug in Baby and No One Knows, so this completely escaped my mind. I plan in writing perhaps more vampire!Shaun in the future, but all oneshots are put on hold while I'm gonna try and do Plug in Baby. Apart from one really, really sad one. Or maybe it'll be happy. I'm not quite sure. Anyways, happy halloween~!

PS: This was beta'd quickly, am I'm exhausted and wanted to get this up for you guys. Reviews = love!

Desmond glanced at Shaun, only to burst out laughing when he emerged from the bathroom.

"What the fuck did you put in your mouth?" Desmond grinned as he leaned back in Shaun's chair, his feet up on the historian's paper cluttered desk. Shaun walked over to him with a cape draped over his shoulders and a grin that revealed two pointy, prominent fangs. He was still wearing his dorky looking grey sweater with the white button up shirt underneath and slightly off black trousers; his auburn coloured hair was still done up in the same faux-hawk way that Desmond hated, as most guys who were assholes styled their hair like that. Although, Desmond wouldn't ever say this out loud to Shaun because he knew, even if he wasn't an Assassin working in the field, he still had a good right hook. Desmond had figured that out the hard way when he sneaked into the historian's room to perhaps uncover a little more of the anti-social man.

"Fangs, my dear Watson," Shaun teased as he walked over to Desmond, adjusting his black and red cape as he did so.

"They look pretty realistic. And you don't talk like you're choking on your own spit, unlike most of those silly plastic fangs."

"Yeah well, they weren't exactly cheap, alright? It's a shame Lucy or Rebecca isn't here, or I'm sure they'd be all over you for your costume," Shaun grinned and tried to kick Desmond out of his chair. Desmond sighed heavily and got up.

"You know I couldn't have gotten a costume, it's not like I had any time or anything," he shrugged and sat his ass on Shaun's desk, much to his annoyance as he made a screwed up face before looking away. "And what the hell could I have dressed up as?"

Shaun contemplated for a moment before he started to put away all his papers into neat, organized stacks. "You could have been Mario or Luigi, although I think Luigi would have suited you more. Nobody really likes him and he never gets the girl," Shaun smirked, stealing a glance at Desmond's frowning face.

"Shut up. Lucy likes me she's just too... too..."

"Not putting out?" Shaun laughed, glancing at a photo of Ezio that was hidden under a pile of texts. If only Desmond was more like him, he might actually be fun.

"No! She's just too shy to confess her love for me," Desmond stated proudly, puffing his chest out slightly. Shaun bit back a cruel remark. "I know I'll be able to ask her out... Perhaps, after all of this will be over. She's too preoccupied with this all at the moment."

Shaun rolled his eyes and slipped the photo away. "Desmond, we're never going to be done with this." He looked up, only to have Desmond look right back at him, his eyes revealing subtle shade of hurt. Surely he knew this whole thing wouldn't fix within a month? "We're Assassins – we're in this for life. And if Lucy can't hold down a relationship during all this, it's her loss. It's called balance."

Desmond blinked stupidly, staring at the historian.

"Did you just say, her loss?"

"Did I?" Shaun looked away from him, running his fingers through his hair. "Or maybe you're hearing what you just want to hear because of your insecurities. I know you, Desmond. You're weak."

"I am not!" Desmond growled and shouted, clutching his fists against his knees as he stared at Shaun, finding his temper rising quickly. "I'm not insecure! I just... Shut up!"

"You can't even form a coherent insult. How do you expect me to fall for you?" Shaun looked at him slyly and grinned, baring his fangs. For several moments, Desmond was at a loss for words as he stared at the faux vampire in front of him. But... Just... How?

"I know you like me, Desmond. I know you like Lucy too but she's too worried about saving the world. Well, we all are but fuck, for the past seven years I've been all work and no play. I want some play time," Shaun growled playfully at him and faked a hiss as he rolled his chair right in front of Desmond. The Assassin still couldn't understand what was happening. Before he could try to get his thoughts in order, Shaun reached out, grabbed his sides and yanked him onto his lap, making sure he didn't fall off him.

"Straddle me, you country boy," Shaun laughed at Desmond's expression, a complex mix between confusion and horror. "You're so weak."

Desmond was about to protest when a pair of lips were pressed against his and he found it quite hard to speak with Shaun's tongue trying to gain entrance into his mouth. With a small groan, Desmond hesitantly allowed him in, feeling his hands run up his back, and felt the historian's glasses pressing against his face. It was a mix of emotions and feelings as Desmond kissed him back, slowly moving his fingers to the back of Shaun's head to pull him in closer. Running his fingers through his hair, Desmond teasingly ran his tongue over Shaun's fake fangs to feel that even if they looked extremely plastic, they were pretty damn sharp. With a sharp gasp, Desmond pulled back, only to see Shaun grin before he pressed his lips against Desmond's neck, sucking gently.

"Y-you're gonna leave a mark..." Desmond squirmed, feeling himself press closer to Shaun without even knowing it until he felt their chests touching.

"I want to – so every other vampire knows that you're mine," Shaun smirked with a sparkle in his eye and instantly, Desmond felt his stomach turn.

"You're such a- ! Shit!" Desmond cried out in pain when he felt a sharp stab puncture his neck. A quick burning sensation shot down his neck and he felt it at the very tips of his fingers as he struggled to pull away from Shaun. His eyes were squeezed shut as he tried to block out the pain, his hands failing to do anything as he tried to figure out what was happening. Something was wrong, very wrong. Desmond wanted nothing more than to scream as he felt his fingers bunch together a handful of Shaun's shirt as he finally found the will to yell. But his pleas of jumbled words and attempts at putting together the word 'help' made no sense as he couldn't get anything logical out, it was just a bunch of letters without vowels that left his tongue. But when he opened his eyes, he knew what was happening.

Those fangs had seemed too realistic to be anything but true. But they fucking were.

Shaun was a vampire.

...And Shaun was sucking his blood.

Desmond tried to shove him off but he felt himself growing tired, as if he had just run a five mile jog and instead of jogging, he had sprinted the whole way. He felt himself turning to goo in this man's hands and he couldn't stop it.

But gently, sure enough, he felt Shaun pull his fangs out and he could feel the blood running freely down into his shoulder, probably staining his hoodie. He looked at Shaun, who was smirking, blood on his bright red lips. His eyes were wild, sharp, ready to pounce on anything that moved. Desmond didn't know if he was dead or not. Whether this historian would be the end of him or not.

"Happy Halloween, love," Shaun laughed as he kissed him and Desmond felt the bitter metallic tang of his own blood before he passed out, going limp in Shaun's arms. Shaun grinned and picked him up effortlessly, cradling him as he carried the body to the large bed in the corner of the room. He tossed Desmond haphazardly onto the bed, grinning as he licked his lips, making sure he got every last drop.

"You taste amazing, Desmond Miles," Shaun grinned as he leaned down to lick the last of the runny blood off his neck before pulling his hoodie up to cover the two bite mark.

"Shit... I don't think I can go in the Animus today, Lucy..." Desmond groaned as he covered his eyes from the harsh sunlight filtering through the window beside him.

"Please, Desmond? We're almost done..." Lucy pleaded, her smile not reaching her eyes. Something was rattling around in Desmond's brain from last night, something about a relationship not possible with Lucy. Where the hell was that coming from?

Desmond rolled on his side, back facing the female Assassin. "I... Yesterday seems hazy... Like I drank too much. But I didn't..."

"Well... Okay, we'll wait another hour or so... Just... rest up," Lucy sighed heavily as she left Desmond to his own and made her way down to Rebecca, who was tinkering around with the Animus. "He's feeling sick... Says last night was a blur... Do you think...? Last night was Halloween... And you know what that means..." Rebecca's eyes quickly met hers and they both glanced at Shaun, who was energetically working on another data base for Desmond. They watched as he happily jumped up and made his way to Desmond's bed and sat on the edge.

"Oi, Desmond, wake up. We have work to do, mate." Shaun reached out and shook Desmond's shoulder violently, getting a rise out of the man.

"Fuck off!" Desmond hissed and gave Shaun a death glare, before something registered in his head. He looked at Shaun's vest, seeing a red tinge stained near the logo of the star. Gears were slowly turning in Desmond's head but the words weren't coming out clear at all.

"Bite me," Shaun snorted, grinning widely to show his perfectly normal teeth. "Get up or I'll work you extra hard in the warehouse tonight, and you'll regret this." With that, Shaun got up and made his way back to his desk, where with an abundance of vigour, he began to write something down frantically and do lively work on his laptop. Confused, Desmond rubbed his sore neck and gently slid out of bed.

"Why are you so energetic?" Desmond mumbled as he walked past Shaun to the Animus, where he sat down, fatigued as he ever had been.

"Oh, I just had a nice midnight snack last night," Shaun smiled as he was typing away and licked his lips in satisfaction.