Summary: On that fateful Halloween night. Buffy is talked into wearing a different costume. When the spell is ended, Buffy finds out she is no longer human, but a Terminator.

Disclaimer: Joss Whedon and Mutant Enemy own Buffy the Vampire Slayer. Annapurna Pictures owns the rights to Terminator till 2019 when they revert to James Cameron.

Pairing: Buffy/Willow

A/U: A/U after from Halloween on. With the exception of Dawn who is A/U from beginning of series.

Author's Note: I know that Terminator: The Sarah Conner Chronicles airs five years after the end of BTVS. I have taken liberties and for the purposes of this story have it airing its first season in 1997. About Buffy being a T-X when Cameron was not. I had a poll up long before I even started this story. The majority of responders (6 out of 10) wanted Buffy as a T-X. So that's why I made Buffy a T-X.

Chapter 1: Halloween

Ethan's was a musty, run-down shop, stocked with every kind of costume imaginable. The place was also packed with kids doing last minute costume shopping. Buffy followed Willow, she wished she hadn't agreed to let Willow pick out her costume. She wanted something that would impress Angel.

"What did you find?" Buffy asked as her younger sister came running up to her.

Dawn held up a package that showed a person with a large white ghost sheet - complete with eye holes, a ghostly smile and the word BOO stenciled on it. "I'm going to be a ghost."

"Okay," Buffy said with a roll of her eyes. She knew Dawn was only going trick or treating for the free candy.

"Ah here we go," Willow said as she stopped in front of a display. There she found two costumes that had come from a recently released television series. "These will do perfectly."

Buffy looked at the costume Willow handed to her. She noticed it came with a gun. "Will. I would rather not have a costume with a gun."

Willow smiled as she took the other one. "Fine Buffy, I'll take the gun. But that's the costume your wearing."

Just then Xander walked over to them. He was still a little sore at Buffy for her saving him when Larry was about to hit him.

"Hey Xander. What did you get?" Willow asked.

Xander opened his shopping bag and pulled out a cheesy orange plastic machine gun.

"That's not a costume," Buffy said.

Xander nodded. "I've got some fatigues from the Army surplus at home. Call me the two dollar costume king, baby."

"Hey, Xander, about this morning. I'm really sorry—" Buffy said.

Xander frowned. "Do you mind, Buffy? I'm trying to repress."

"I promise I'll let you get pummeled from now on," Buffy said.

"Thank you," Xander said as he released his anger. "Okay. Actually, I think I could have—"

"Buffy! I want to go," Dawn said.

Buffy sighed. "I couldn't get you guys to take Dawn off my hands tomorrow night?"

"Sure, I'll do it Buffy," Willow said.

That night Buffy looked at the costume, other than the plastic gun Willow had taken with her, the costume looked nice. Not really much different than clothes she might normally wear. The main part of the costume was in the makeup and temporary tattoos that were design to make it look like there was a robot beneath the skin.

"Buffy?" Dawn said from Buffy's door as she turned to face her sister. "How come I can't go with you tomorrow night?"

"You really want me to go with you tomorrow night?" Buffy asked. "I might steal your candy."

"Good point," Dawn said.

The next night Buffy watched as a group of trick or treaters came up to her, looking dejected.

"What'd Mrs. Davis give you?" Buffy asked as the kids all opened their hands, revealing brand new toothbrushes. "She must be stopped. Let's hit one more house. We still have a few minutes before we've got to get back."

On Mrs. Parker's porch Willow stood with her group next to Dawn as the front door opened, revealing the smiling face of Mrs. Parker.

"Trick or treat!" The kids said.

Mrs. Parker smiled. "Oh my goodness. Aren't you adorable!"

Down the street Buffy ushered her group down the block as a gust of wind sent a chill down her back. She stopped as if she sensed something was not quite right.

Back at Mrs. Parker house Mrs. Parker looked in the plastic pumpkin she held, a look of concern crossing her features. "Oh, dear. Am I all out? I could have sworn I had some candy left –" She looked at one of the kids. "I'm sorry, Mr. Monster. Maybe I—"

Her words are silenced by the death grip of a gargoyle that had been seconds before one of the kids.

"Let her go!" Willow said as she moved to help.

"Willow," Dawn said as she gasped out.

Willow looked at Dawn who was gasping for breath. Behind her the transformed kids attacked each other as Mrs. Parker scrambled back into her house, slamming the door behind her.

"Dawn?" Willow asked as Dawn crumbled to the porch as her body went limp, lifeless. "Dawn?"

Down the street Buffy stood immobile.

SYSTEMS CHECK... PROCESSING

SYSTEMS... ONLINE AND FUCTIONING AT 100%

0 – 0 – 0 – 0 – 0

QUERY: UNIT CURRENT LOCATION?

GPS SYSTEMS ONLINE

SCANNING FOR GPS SATELLITE SYSTEMS... LOCATED

UNIT CURRENT LOCATION: SUNNYDALE, CALIFORNIA, UNITED STATES, NORTH AMERICA

0 – 0 – 0 – 0 – 0

QUERY: MISSION PARAMETERS?

DISPLAYING MISSION PARAMETERS...

0 – 0 – 0 – 0 – 0

PRIMARY OBJECTIVE... LOCATE AND IDENTIFY PRIMARY SUBJECT

PRIMARY SUBJECT... JOHN CONNOR

PRIMARY DIRECTIVE... INSURE SURVIVAL

SECONDARY DIRECTIVE... PROTECT

0 – 0 – 0 – 0 – 0

SECONDARY OBJECTIVE... LOCATE AND IDENTIFY SECONDARY SUBJECT

SECONDARY SUBJECT... DAWN MARIE SUMMERS

PRIMARY DIRECTIVE... INSURE SURVIVAL

SECONDARY DIRECTIVE... PROTECT

0 – 0 – 0 – 0 – 0

TERTIARY OBJECTIVE... SEARCH AND TERMINATE

TERTIARY SUBJECT... GLORIFICUS

PRIMARY DIRECTIVE... PROTECT DAWN SUMMERS FROM GLORIFICUS

SECONDARY DIRECTIVE... TERMINATE GLORIFICUS

Cameron looked blinked as she reviewed everything and started off to find John Connor and Dawn Summers.

On Mrs. Parker's porch, John Connor looked around trying to think of where he was. He had been sitting with mom moments earlier. And now he was standing on someone's front porch. How did he get here? And where was here?

Dawn slowly sat up, emerging from her dead body, which remained unmoving on the ground. "Willow?" she said as she noticed her feet sticking out of the ghost sheet. Dawn had become a real live ghost.

John looked around him when he heard the girl's voice and looked down, what he saw sent his eyes wide and he backed away. "W—what are you?"

"Willow?" Dawn said, her voice barely more than a whisper. Her eyes were wide with fear. What had happened? How had she become a ghost? Was she really dead? "What's wrong with me?"

"Why do you keep calling me Willow?" John asked. "My name is John, John Connor."

Even though Dawn had never seen the Terminator movies or the new TV series. She recognized the name since she had asked Willow who her sister's best friend was going as.

"You're Willow," Dawn said. "You're my sister's best friend. You're mine, too."

John looked at Dawn and shook his head. And that was when he noticed something was different as a strand of red hair flew in front of his eyes. He grabbed some of his hair and noticed it was indeed red. Two things immediately struck him. The first he didn't have red hair, his hair was black. The second it wasn't that long, he always kept his hair cut short. He looked down and as he did his eyes went wide. What he saw was enough to make him stagger back in shock. He was now a woman.

Before John had time to deal with that revelation he and Dawn heard the sound of machine gun fire as they turned their heads and saw Xander backing across the street, looking around him in silent panic.

"Xander!" Dawn said as she got up and ran across the street momentarily forgetting her body. Luckily John didn't as he picked up her body and then turned and followed her, shaking his head the entire time.

Xander whipped around and pointed a gun right at Dawn.

"Xander, it's me," Dawn said. "Buffy's sister, Dawn."

Xander cautiously lowered the gun a little. "I don't know any Dawn."

"Oh now," Dawn said. "Not you two."

"Soldier," John said. "Identify yourself."

"Reese, Kyle," Xander said. Sergeant/Tech-Com, DN38416..."

John frowned. He knew what his father looked like. His mother had managed to find a picture of him from police files years after he had been born. "You are not Kyle Reese."

"What are you talking about?" Kyle said.

"I know what Kyle Reese looks like, he's my father."

Kyle looked at John confusion on his face. "Father? I have no kids. I was sent back in time to insure the safety of Sarah Connor."

"My mother," John said.

"That's not possible, ma'am," Kyle said. "Sarah Connor had only one child, a son. John Connor."

John sighed. "Looking I'm John Connor. How I wound up as a woman I don't know." He looked at Dawn. "Do you ghost girl?"

Dawn shook her head. "Sorry. I don't know either. But I know you're not John," she said. "Your name is Willow." She looked at Kyle. "And you're, Xander."

Just then Dawn spotted Cameron and ran over to her as she was approaching them. "Buffy! Am I glad to see you!"

"Dawn Summers?" Cameron said. "You must come with me if you want to live."

John frowned as he recognized the line that the Terminator had given him and his mother when it had come back from the future to protect him. "Who reprogrammed you?" he asked as he walked over to Dawn and Cameron.

"I was reprogrammed by John Connor and Dawn Summers. I was sent back to protect them," Cameron said.

John looked at Dawn and then at Cameron. "What series are you?"

"I am a T-X," Cameron said.

"I am unfamiliar with that series," John said. "Despite what I currently look like I am John Connor and this is Kyle Reese." He waved at Xander who had been listening.

Dawn nodded. "Something crazy is happening," she said. "I was dressed as a ghost for Halloween and now I am a ghost. Xander, you were supposed to be a soldier and somehow became this Kyle Reese. Willow you told me that you and Buffy did a theme. You were going as someone named John Connor and Buffy was going as someone named Cameron."

"And you expect us to believe that?" Kyle asked.

"I know, Cameron," John said. "She was sent back to protect me. But Cameron was a T-900. Not a T-X." (A/N 1)

Just then a little vampire emerged from the bushes as Xander aimed at it.

"No!" Dawn said. "That could be another kid like me!"

"She has a point," John said. "Till we figure out what is going on here. We should not risk hurting anyone. She could be right that we are these people and not who we seem to be."

"My house," Dawn said, "is not too far away. We could go there so you guys can figure out what's going on."

"We should get off the street," Cameron said as Dawn led them down the street.

The back door of the Summers home opened as Dawn rushed in followed by John, Cameron and Kyle.

Kyle closed the door and looked out the window. "I think we're clear."

"Mom, I'm home!" Dawn yelled out but received no response. "She must be still at the gallery."

A violent pounding on the front door startles them all as Kyle started with the others right behind him.

"Don't open it!" John said as he sat the girl's body onto the couch in the living room.

"It could be a civilian," Kyle said.

"That is an order, Reese," John said.

In the dining room Dawn noticed that Cameron was looking at a picture. "That's you, me and mom," Dawn said. "Don't you remember, Buffy?"

"You're sister, if my files are correct," Cameron said. "I was programmed with her form so that I could show you a face you would recognize."

"No," Dawn said. "You're, Buffy. You're my sister."

In the living room, "Do you think it's a wise idea to bring a long the Terminator?" Kyle asked.

"Terminator's can be reprogrammed, Kyle," John said. "My future self, reprogrammed and sent a T-850 back a few year ago to protect me when a T-1000 was sent back."

"T-850, T-1000, T-X?" Kyle said. "How far forward are you from? And how far forward do you think she is. The only Terminator series we know of is the T-800 and earlier."

"I'm from about 16 years in the future from the point you were sent to protect my mom," John said. "I would assume the Terminator is from further ahead than that."

Just then the pounding started again as Kyle looked out the window of the door again. Suddenly a hand smashed through the window grabbing him by the throat as he jumped back.

"Warning shot only," John said

Kyle nodded as he stuck his gun out the window and fired above the head of the thing that had grabbed him scaring it off. Just then they heard someone scream. He looked out the window. "Civilian," he said.

"Go," John said as Kyle burst out the door. A moment later Kyle returned with Cordelia.

"Cordelia, right?" Dawn asked.

"What's going on?" Cordelia asked.

"Not sure," Dawn said. "But you do remember your Cordelia right?"

"Yes," Cordelia said. "So what's going on? I was just attacked by Jo-Jo the dogfaced boy. Look at my costume! Think Party-Town's gonna give me my deposit back? Not on the likely."

"Not sure what is going on," Dawn said. "But Willow, Xander and Buffy don't remember who they are. And it seems I'm a ghost."

Cordelia looked at Dawn as if to say yeah right.

Dawn sighed and walked through Cordelia and over to the couch and motioned toward her body. "I seem to have become a ghost."

Cordelia noticed a particularly big rip up the side of her costume as Kyle took his jacket off and draped it around her. "Here," he said.

"Thanks," Cordelia said.

"Okay, I think it might be time to get help," Dawn said. She looked to Cameron. "Do you know where my sister would have gone for situations like this?"

Cameron nodded. "The High School."

Dawn nodded and started for the door as John moved in front of her. "You maybe a ghost here," he said. "But we don't know if there isn't something that can't hurt you out there."

"Then maybe someone should come with me?" Dawn suggested as she looked at Cameron.

"I will go with her," Cameron said as John opened the door. She followed Dawn out of the house leaving John and Kyle alone with Cordelia and Dawn's body.

"We should barricade ourselves in," John said. "Till we hear from the Terminator and ghost girl."

Dawn led Cameron across town. Every time a kid sized demon approached them, Cameron scared it off. Dawn had asked Cameron not to do anything to harm them. Cameron had complied. Dawn and Cameron found Giles at the card catalog. He looked up at them when he heard the doors close behind them.

"Mr. Giles," Dawn said. "Hi. Uhm …"

"I am a T-X series Terminator," Cameron said. "We have come to you because of something that you might be able to help us with."

"Buffy, why are you talking like that?" Giles asked.

"She's not Buffy," Dawn said. "Not right now at least. Just like I'm a ghost."

"A ghost?" Giles asked, skeptical.

Dawn sighed as she passed her hand through the wall next to her. "Yeah I think everyone became their costumes. Maybe not everyone. Cordelia didn't become hers."

"Cordelia?" Giles said.

"Cordelia Chase," Cameron said.

"She did not change into her costume?" Giles asked. "Dawn do you know where she got hers?"

"She said Party Town," Dawn said.

"And yours and Buffy's?" Giles asked.

"Buffy said we were going to a new place. Ethan's I think," Dawn said.

"Do you remember where?" Giles said as Dawn nodded.

Giles drove Dawn and Cameron to the costume shop. They noticed that the front of the shop was dark. "Whatever you two do, follow my lead," he said as led them inside. "Hello? Is anyone in?"

They made their way through and into the back room as they searched for the proprietor of the shop.

"Mr. Giles," Dawn as she spotted a bust of some person.

Giles followed Dawn's gaze and looked at the statue. "That's Janus, a Roman mystical God."

"What does it mean?" Dawn asked.

"Primarily, it represents the division of self. Male and female. Light and dark—" Giles said.

"Chunky and creamy style. No, sorry. That's peanut butter," Ethan said as he stepped from the shadows, smiling at Giles.

Giles stepped in front of Dawn and Cameron, never taking his eyes off Ethan. "Dawn go with Buffy, now."

"But –" Dawn started to protest.

"NOW, Dawn," Giles said.

Dawn bolted as Cameron followed her outside. They hadn't made it very far when they ran into a man. Dawn recognized him from Buffy's parent/teacher night the month before as Spike. She looked over at Cameron.

"Well, well, Slayer," Spike said.

Cameron's heads up display showed that Spike's body temperature too be sixty-two point three degrees Fahrenheit. She searched the memory files she had for Buffy Summers and came to the conclusion this was a vampire. She morphed her arm as she raised it to point it at Spike. "You have been terminated, vampire." Suddenly a jet of fire spewed forth from the transformed arm at Spike who caught on fire and dusted.

As Cameron morphed her arm back to normal, Dawn disappeared. It was then that Cameron suddenly remembered who she was, Buffy.

"Dawnie?" Buffy called out looking around for her sister. "Dawnie where are you?" Behind her Giles stepped out of the store.

"Buffy?" Giles said.

Buffy looked at Giles. "Dawn's missing. And I think something is wrong."

"Okay, we'll find Dawn," Giles said as they walked down the street to his car. "What do you think is wrong?"

"I think I'm still a Terminator," Buffy said.

"A Terminator?" Giles said. "You mentioned that in the library. What is that?"

"A Terminator is a type of Hunter-Killer designed to terminate other life forms," Buffy said as she accessed files through her internal heads up display. "Terminators are built by an artificially intelligent computer called Skynet, in order to wipe out the remains of humanity after Judgment Day. I'm basically an assassin type robot."

Giles stopped and looked at Buffy. "You are a robot now?" he asked.

Buffy nodded as she raised an arm and it morphed into the flamethrower. "Pretty much," she said as she fired the flamethrower, sending out a jet of fire. "And that is just one of my many weapons."

Giles eyes went wide as Buffy touched his shoulder. Then he watched her morph into duplicate of himself.

"A robot," the Buffy-Giles said. "A very advanced one at that." She morphed her form back to normal. "I guess you could say I've become the ultimate Slayer."

"Right," Giles said as he stood there going over the ramifications of Buffy being no longer human. Had the Slayer line passed on or had it ended with Buffy's metamorphosis from human to machine?

"Buffy!" came a yell as they turned to see Willow, Xander and Dawn running toward them.

Buffy wrapped her arms around sister seconds before a display flashed across her display:

UPDATING OBJECTIVES

PRIMARY OBJECTIVE... LOCATE AND IDENTIFY PRIMARY SUBJECT

PRIMARY SUBJECT... JOHN CONNOR – DOES NOT EXIST. CHANGING PRIORITY OBJECTIVE TO WILLOW ROSENBERG

PRIMARY DIRECTIVE... INSURE SURVIVAL

SECONDARY DIRECTIVE... PROTECT

0 – 0 – 0 – 0 – 0

SECONDARY OBJECTIVE... LOCATE AND IDENTIFY SECONDARY SUBJECT

SECONDARY SUBJECT... DAWN MARIE SUMMERS

PRIMARY DIRECTIVE... INSURE SURVIVAL

SECONDARY DIRECTIVE... PROTECT

0 – 0 – 0 – 0 – 0

TERTIARY OBJECTIVE... SEARCH AND DESTROY

TERTIARY SUBJECT... GLORIFICUS

PRIMARY DIRECTIVE... PROTECT DAWN SUMMERS FROM GLORIFICUS

SECONDARY DIRECTIVE... TERMINATE GLORIFICUS

Buffy looked down at Dawn for a moment as she wondered who this Glorificus was. She could have sworn for a second she had heard a female voice in her mind that stated.

"Glorificus is a Hell God"

"Buffy?" Xander said noting the look on Buffy's face.

"I'll tell you tomorrow," Buffy said. "I have to get Dawn home."

The next morning at Sunnydale High, Buffy walked down the hallway leading to the library looking at the students around her who had no idea she was no longer human. She let out a sigh. At least now she didn't have to worry about dying from a vampire. But it also meant she could no longer have children. Not that she had thought much about having children. She was only sixteen going on seventeen after all. Children would have been down the road if she had lived that long.

She walked into the library and saw that Xander, Willow and Giles were waiting for her.

"I filled them in on what you showed me," Giles said.

Buffy smiled at Giles in appreciation.

"So you're really a Terminator now?" Xander asked.

Buffy nodded. "Yeah," she said. She let out a sigh. "I looked over several files last night, since I pretty much no longer have to sleep. Willow it seems while our costumes matched. Something happened and I think I may have come from an alternate world compared to your John."

"I was wondering that myself," Willow said. "John had said that Cameron was a T-900 not a T-X.

"He may have been right about his Cameron," Buffy said. "But I'm not, I'm a T-X. I have two primary objectives. The first was insuring the survival of John Connor. The second was insuring the survival of Dawn Summers."

"What?" Willow and Xander said.

"It seems in the reality that my Cameron came from. My baby sister was John's second in command," Buffy said. "That's not all. The moment the spell ended one of the primary objectives updated itself. I assume it's a result that I knew that the show our costumes were based off of was one of fiction. Anyways it now has me insuring your survival, Willow. I don't know why."

"I think I do," Willow said. "I still have John's memories."

"As I have Kyle's," Xander said.

"I half expected that might be the reason," Buffy said. "Dawn even was affected."

"But she's no longer a ghost," Willow said.

"That's right," Buffy said. "She seems to have gained the ability to phase through walls and stuff like a ghost would. But she's still alive."

"Kind of like Kitty Pride," Xander said as everyone looked at him. "X-Men comics. She can phase through solid matter."

"So you have weapons that can help you as a Slayer," Giles said. "You have information literally at your fingertips. Does these primary objectives tell you why you have to protect Willow and Dawn?"

"No on Willow," Buffy said. "Willow I think is just a replacement since she has John's memories. Dawn on the other hand yes. Sometime in the next few days, weeks or years someone named Glorificus will come after her. That's my third objective. Protect Dawn from Glorificus and then terminate Glorificus. I'm still reading through files so I don't know exactly why. But I do know this. This Glorificus is a Hell God."

Xander, Willow and Giles looked at each other, a look of shock mirrored on each of their faces.

Author's Note: A/N 1 – Cameron's Series Number. There is some discrepancy on what series she is. One Reviewer says she is a T-888, Terminator Wikia lists her as a T-900 and another reviewer lists her as a Tok-715. The Tok listing came from an ad for the show, if I remember right. But there is NO mention anywhere in the show of what she is. So there is some question on the correct series number. I went ahead and used T-900 for simplicity sake.

Please do not keep sending reviews in stating she is this series number or that series number. I actually did research to try and find out her series number before I started this chapter. And as I said her series number is not mentioned anywhere in the series. As far as Canon is concerned any of the series numbers could be correct or none of them. We don't know. So again I used T-900 for simplicities sake.