Okay, I'm attempting to write a Doom/Buffy crossover. It's a crossover from the movie, so don't bite my head off or anything. I just saw the movie last night. And Yeah, I know, there's time differences, but deal with it, okay? I'm going to do the best I can. Oh, and there will be spoilers for the movie, so if you haven't seen it, I suggest you do.

Los Angeles Califonia-10:46 PM

John pulled his car into the driveway. Most of the lights were still on. That was a good sign, Sam hadn't gone to sleep yet. As he stepped out of the car he breathed in the sweet ocean air.

The front door was locked, also very good. After what had happened recently, he had become slightly paranoid. He didn't even like to think about it. He pulled his keys out of his pocket and was about to open the door when a car pulled up.

Sam's friends, probably, John thought as he watched a blonde and a brunette(She must be nineteen. She doesn't look that old) got out of the car.

"Uh, Hi. I'm Buffy Summers, my sister Dawn. Is Sam home?" The blonde asked. John nodded. He turned to open the door, but Sam opened it first.

"Oh! Hi, John. I was wondering why two cars were outside. Um, Buffy, Dawn, come inside." Sam smiled. Her hair was pulled up, tied out of her face. That always meant she was working on something.

John hung his coat up and walked into Sam's lab.

Buffy was sitting in a chair, her sleeve rolled up. Sam was testing a blood sample. Dawn also had her sleeve rolled up.

"Yep, its there. Odd. You said you were born with this?" Sam asked, and Buffy and Dawn nodded.

"What is it?" John asked. He had a feeling he wouldn't like what he was about to hear. Buffy unrolled her sleeve.

"She has the twenty fourth chromosome, and so does her sister. And apparently all of the people like her." Sam downloaded the data into a chip and put it into a safe.

"Damn. How many of you are there?" John asked. Buffy shrugged. He didn't like that.

" Hundreds, maybe. We're all born like this, but only one is chosen for the gift. If the chosen one dies, another one is chosen. But a friend of mine did a spell that made all the potentials actually strong and quick like me." Buffy explained it the best she could. She really didn't understand it much herself.

"Well ain't that charmin'?" Buffy whirled around and found Caleb and The First standing there. Out of the corner of her eye, she saw John and Sam flinch. She didn't know who The First was impersonating, but obviously they didn't like him.

"What do you want? How many times do I have to kick your ass?" Buffy asked, discreetly moving into fighting stance. She saw Dawn move behind her.

"Until the end of time, Slayer. I'm immortal, never forget that. I can do whatever I want. Oh, and nice to see you again, Reaper." The First smirked then disappeared.

How did they get in here? Sarge was dead, I know it. John curled his hands into fists.

Caleb smirked. "Who am I goin' to kill first, huh? The pretty little girl here?" He gestured towards Sam.

"You lay a hand on her and you're going to wish you had never existed." John growled, and Caleb chuckled.

"Or the little girl here? I bet the Slayer won't let me touch her either. I guess I have the two of you to deal with." Caleb laughed.

"You could have to deal with me too, you know." Caleb turned around. Spike was standing there, game face on.

"Hello, Spike." Sam grinned. Buffy shook her head.

"Well, I'm in trouble, ain't I? I better be quick then. I have to kill all the potential slayers, you know that." Caleb rushed Sam, but John was quicker. Caleb was across the room before Buffy could take two steps.

"I warned you not to touch my sister, didn't I?" John asked, watching Caleb slowly get up.

"You can't be that fast! Its impossible!" Caleb stuttered. John shrugged.

"Hey, It wasn't my idea." John started towards Caleb, but he turned and fled out of the room, leaving by window. John sighed. He had hoped he had never needed to use his strength again.

"How….How did you do that?" Dawn asked.

"Potential Slayers?" Spike added

"Do you have a night job?" Buffy questioned.

John sighed again. "Sam, could you explain, please? You know what happened better than I do."

The phone rang just then, and John reached for it. It was probably the commander, asking him again if he had gotten another team yet.

"Hello?" No answer. He shrugged and hung up.

"John is part of the RRTS, Rapid Response Tactical Squad. He went to Mars to stop hostile forces, something you would call demons, and the UAC was experimenting on humans. Humans only have twenty three chromosomes, and they had synthetically made the twenty fourth chromosome. It mutated some people, made others super strong. John was given super human strength and speed. The rest of his squad either was killed by the mutations or was killed." Sam explained, leading them out of the lab.

"You guys want anything?" John asked, grabbing a beer out of the refrigerator.

"Um, got any Coke?" Dawn asked. Buffy didn't want anything, and neither did Spike.

"Here" John tossed her a Coke.

"Thanks."

Buffy's cell rang, and she answered it.

"Yeah? What do you mean, is Joyce with me? I left her with Willow. You're shitting me, right? No, I think I know where she's at. Cordy's. Okay, I'll see you later." Buffy put the phone away.

"What's up?" Spike asked, curious as to where Joyce was at.

"Joyce left Willow's."

"Do you need help looking for her? I mean, that crazy preacher guy is still out there. Is she like your sister or something?" Sam asked, and Spike shook her head.

"Our daughter. Willow did some magic spell thing, and she's eighteen. In reality, she's only four." Spike explained.

"Maybe you better come. Caleb looks like he got stronger. A lot stronger." Dawn said, looking at her watch.

"Sure. Let me get my coat. John, you coming?" Sam pulled off her lab coat and headed towards the door. John was digging through a trunk by the couch. He pulled out a black vest.

"Hell Yeah." John pulled the vest on, and pulled a nasty looking gun out of the trunk.

" Bio scan completed. Codename-Reaper." The gun said. Spike grinned. Nice name. Wonder how he got it.

Sam shook her head, and pulled on a coat. She really couldn't say anything, she started walking around with a handgun in her pocket since what had happened not to long ago.

"Lets go."