Only a Slayer

Summary: An Initiative experiment goes very wrong. Very, very wrong. Warning: Massive deaths. *Slight crossover with Smallville*

Challenge: couldn't find any, but if you know of one it fulfills, let me know.

Timeline: season 4 'The 'I' in Team'. Only a slight crossover with Smallville, post season 4. The Mr. Luthor mentioned is Lex, not Lionel.

A/N: You may not agree with my reasons for things in this story, but the idea was to be as brutal as possible.

Warning: Massive deaths.

Thanks to my betas: none. I want to shock them, too.

Disclaimer: BtVS and AtS characters belong to Joss Whedon / Mutant Enemy. Smallville characters belong to DC Comics & WB. I claim no rights to any copyrighted material. Please do not copy or take this story without my permission.

Maggie Walsh's office

Staring at the lead box in her hands, Walsh knew she had a decision to make. Riley's little girlfriend was poking her nose where it didn't belong more and more. If she were allowed to dig any deeper, she would find the green meteor rock-powered hybrid Walsh was building. That was Mr. Luthor's pet project, and nothing could be allowed to derail it; not when it was so close to its completion.

One option would be to send Miss Summers out into the field with faulty equipment, but the scientist in her wanted to conduct an experiment instead. Inside the box was something supposedly able to replicate a human body when exposed to it. If she used it on the Slayer, she could keep one in the secret part of the lab while letting the other one resume her life; no one would be the wiser and she would have a Slayer to study.

"Please find Miss Summers, and have her report to my office," she commanded her assistant over the intercom. Moments later, the annoying blonde bounced her way in…no professionalism in that girl. "One of the teams found something and I was wondering if you might be able to identify it," Walsh stated, holding the box out with the lid open.

Buffy took a look inside and raised an eyebrow. "A black quartz rock?"

Frustrated that the nuisance hadn't touched it yet, Walsh thought of an excuse to make her. "There are some markings on the bottom in a language we don't recognize."

Even though her instincts were telling her to throw the box at the professor, Buffy remembered that she promised Riley that she would try to make nice with the people he worked with down here. Sighing, she reached inside to grab it, then felt the worst pain imaginable when her skin came in contact with it. Damn it! It was a trap of some kind!

Walsh watched with clinical fascination as the split took place. It was amazing at how precise the replication was…right down to the very clothes on Miss Summers' back. Both subjects fell to the ground when it was complete. Walsh thought for a moment about which one to keep, then decided it would be best to wait until they woke up – in separate rooms, of course – to see which one sounded more like the ex-cheerleader.

She had just secured one of them and made it back to her office when the other one's eyes flashed open. Best to play the concerned mentor. "Miss Summers, I'm so glad you're alright." Stepping forward to help the blonde stand, Walsh stumbled right back when she heard the girl growl and her eyes turn black.

"Evil doctor. Tried to kill me," Buffy snarled. She tilted her head to the side as if studying a bug. "I kill evil," she finally concluded.

Walsh's screams were loud enough to alert some nearby retrieval teams, but when they burst into the office to fight whatever creature attacked her, they too were ripped apart by the feral Slayer. Her survival instinct was running so high at the moment that anyone or anything that approached her would meet the same horrible death. The entire building reeked of evil to her. That meant she had to bring it down…all of it.

As she made her way through the containment area, annihilating all the demons held captive there, more teams came to take her down. While an ordinary Slayer might have been captured, this was the full-version they were dealing with. She was able to erect a shield around herself that wouldn't allow anything to strike her: tasers, bullets…hell, one soldier who was a fan of Stargate even tried to throw a knife at her, hoping it was similar to the Goa'uld personal shield. It wasn't.

Everything they shot or threw at her was turned back on them, killing them instantly.

When all the demons were dead and all the humans who were foolish enough to come after her joined them, she started to think about the best way to destroy this building. While she may have been feral, the Slayer had a swift learning capacity. With access to all past and present Slayers, she began her search for the Initiative's stockpile of C4. Then she found a manual on how to use it properly, and like any weapon, she learned very quickly.

Practicing on the rooms until she felt comfortable with it, she then looked for schematics for the facility so she would know the best places to put the explosives. The important thing was to cause the building to collapse on itself, not to blow outward – which would risk innocents.

Some time later, she was standing outside again, holding a detonator in her hands and facing the frat house which stood guard over the entrance to that pit of evil. A pulled fire alarm emptied the house of its occupants, so the Slayer decided to act now, before the fire department showed up and was put at risk.


Smiling in satisfaction as she watched it collapse, the Slayer crushed the detonator and dropped the pieces into nearby garbage cans. Now that that place was taken care of, it was time to rid the world of evil.

Random cemetery

As the feralness began to subside a little, the Slayer was able to sense which demons were evil and which were peaceful. It would astound the Council to learn that even a feral Slayer would not choose to kill innocent 'demons'. That didn't include evil demons with behavior chips in them, though. The chips were like leashes, which – if broken – would release the evil ones back into the world. Her compassion for non-evil demons didn't extend to humans touched with demonic evil, however.

Walking through the town, the Slayer killed black magick people, ex-demons who still reeked of the evil they sowed in their past, even a couple people who had been possessed by animal spirits. Any that touched evil and had enjoyed it…even a little bit. Even those that wore the faces of people who Buffy Summers loved.

She followed the scent of evil to wherever it lurked and killed it. There was one human who shared his body with evil, and used black magick to clean up after his alter ego. Unfortunately, she didn't know a way to deal with the Hellmouth, so she did the next best thing: made Sunnydale so scary to evil demons that few would dare to come there.

By the time she finished, days later, Sunnydale's population had decreased by 50% – if demons had been counted in the census, that is. The human population merely decreased by a couple dozen souls. The only demons left were those who didn't pose a threat to humans. They would serve as a warning to other demons that came to Sunnydale. If anyone intended to harm humans in that town, the Slayer would be back to take care of them.

As the Slayer headed out of town, the rescue teams recovered the body of a college coed in the rubble underneath the fraternity which collapsed the previous week. Her mother, Joyce Summers, made the identification.

Another time, another place…

The Slayer's next stop was Los Angeles. She did the same thing to the Wolfram & Hart offices that she did to the Initiative, this time without pulling the fire alarm.

As she cleaned out the demon community, she hesitated when she ran across the souled vampire. In the end, however, the demon within was stronger than the soul which struggled to hold it back. If the magick locking it in place were to vanish…well, it was similar to the behavior chips in Sunnydale.

Then there was the betrayer to take care of. The Slayer who used her abilities to help evil spread; that had been a little trickier given the traitor's location. The prison officials were never been able to solve the mystery of how the brunette was murdered in her cell down in solitary.

From then on, the Slayer roamed the Earth, following her senses to where evil lived. The Council tried a couple times to capture the 'rogue' Slayer, but after a few teams were sent back, some of them in boxes, they left her alone, hoping that she would never turn on humans once the demons were gone.

The demons started to leave the dimension as her reputation grew. With her systematically taking out all the branches of Wolfram & Hart around the world – despite their best efforts to catch her – Earth just wasn't worth the danger it now posed. Still, there were some who thought they could beat her. After all, she was only a Slayer. They were wrong. Very, very wrong.

A/N: I tried to be dark without being gory.