Disclaimer: I do not own Buffy the Vampire Slayer, anything from Marvel Comics, and any other possible crossovers that will show up later in the story.

"Buffy the Vampire Slayer" trademark and copyright 20th Century Fox Television, Mutant Enemy, Kuzui Enterprises, Sandollar Television, and Dark Horse Comics, Inc. Fox apparently owns all the mutants, including Apocalypse.

AN: I know... I'm sorry that I was away for so long. For what it's worth, I haven't stopped working on this story, even if I've had to do a huge rewrite to fix a plot hole that only became apparent after some time away. It's kinda funny though, in attempting to close one big plot hole, I actually managed to create five more. It's okay though, it's all fixed now. Still, be glad because the original fix involved bringing a character, (Kennedy *shudder*) into the story at the beginning instead of season 7 and now I don't have to do that.

I've put a lot of work into this story and I have no intention of quitting anytime soon. Enjoy the return to Xanderpocalypse..

Chapter 01 – Halloween Causality

Returning to where his life truly began for the first time since his endlessly long adventure began felt less like coming home than Xander Harris had expected. He thought that coming here would feel like the completion of some long mission, the goal being to reach home, but as the sapphire blue Jaguar XJR passed the 'Welcome to Sunnydale' sign, he just felt out of place. How could he explain to those that called him friend what had really happened that Halloween night or how long it had been for him since he saw them last? Every time he thought about it, he couldn't find the words. It was funny as he had, after all, been thinking about it for a really long time. They wouldn't understand and they wouldn't believe. He could of course prove everything that had happened to him, but any action he took that made him seem anything other than normal would cause them to lash out.

'Joy, this will be fun.' he thought to himself as the car round the corner. 'Who would have thought that time travel could be such a pain?'

Xander was pulled from his inner dialog by the flash of red hair and a cry of pain coming from the mouth of an alley they were passing. The screech of the brakes was loud in the night as he forced the car to a stop, the passenger thrown forward against her seat belt. Before she could do more then cry out in surprise he was out of the car and running into the darkness. He quickly fell upon the vampire that held a red-headed woman to the wall and was drinking from her neck. A flash of a blade and the dust, all that remained of the demon, raining down was only a momentary distraction as Xander took hold of the woman, pressing a hand to her wound to staunch the bleeding. She was probably another victim of the Halloween spell that turned people into what they dressed as that night, judging by the skin-tight red and gold costume of Marvel comic book character Jean Grey. Being that close he was able to easily make out that the woman below the red wig was Jenny Calendar, the computer teacher of Sunnydale high.

Consciousness was a fleeting thing for the woman, awareness coming and going in fits. The first thing she became aware of was a dark haired man holding her upright and tending to her wounds. Darkness enveloped her for a bit only for her to awaken once more in the back of a car being driven by a different, though familiar looking man who was speaking to a red-haired girl of indiscriminate age in the passenger seat. Her head felt like it was full of cotton and she could only make out snippets of what they were saying.

"-way to soon, she shouldn't be awake yet." She could hear the man saying.

"She's your friend. What are you going to-" the girl replied, though her question was incomplete as the darkness again descended on Jenny's mind once more.

The movement of the car stopping drew the teacher back to consciousness a second time.

"-I'm taking her in to the others." The familiar looking man was saying. He suddenly glanced at her lying prone in the backseat, she blearily blinking up at him. "Damn, she woke up again. That costume really did a number on her."

Unconsciousness once more swept Jenny's mind away. She woke a third and final time to find herself sitting on the ground and leaning against the side of a building with another dark haired male standing over her, only this one younger than the others.

"Mrs. C? You okay?" the boy asked, gently checking her for signs of injury. The woman snapped fully awake with a start and reached up to her neck, only to find a bandage taped over the wound.

"Xander?" The woman questioned, "What's going on?"

"I don't know. I found you here on my way into the school." She looked around and found he was right, the building she was leaning against was the main entrance to Sunnydale high school. She tried to think over what had happened, her mind coming up with a vampire attack, then a dark haired man... no, two dark haired men and a red-headed girl in a car. The teenager took hold of her arm in a surprisingly firm grip and helped her to her feet. She leaned against the building for a moment to let the vertigo pass before standing fully upright.

"I'm okay."

"Good. We should get inside, the others are probably waiting for us."

"The others..." Jenny muttered, her mind flashing back to the words of the man in the car. 'I'm taking her in to the others'. That was the moment when it hit her why the second dark-haired man in the driver's seat looked so familiar. It was Xander... only older.

Once she was stable on her feet, Xander led the way into the building and directly toward the library where they found four teenagers sitting at the main study table.

"Xander!" Cried a targeted red-haired missile moments after leaping from her chair and speeding across the room only to slam into his chest hard enough to knock him back a step. "I was so worried when everything went wonky and there were vampires and you disappeared and I thought they brought you back to their lair and you were dead or... or turned and they were drinking you like a smoothie and then you would come back to eat us all and we would have to kill you and oh it would be so terrible! So where did you go?"

"Hello, everyone!" He called to the rest of the room after Willow, his very first friend, stopped her flow of unedited thought. Despite his earlier feelings of unease it hit him just how much he'd missed her, missed all of them. As soon as she let go he was pulled into a rib-cracking hug by the blonde vampire slayer Buffy Summers. She wore a full Victorian-style evening gown which was opposed by Willow's manner of dress, that of a leather skirt, knee-high matching boots and a red top that was cut low and exposed her bare midriff, very unlike her usual attire.

"Man am I glad to see you are okay." His oldest male compatriot Jesse McNally said from his place at the study table. "I was worried I'd have to find a new best friend."

Xander snorted, his voice dripping with sarcasm. "You'd be stuck as the only guy amongst a group of girls... oh the tragedy."

"Don't even think it dweeb-boy." Cheerleader and self proclaimed 'queen of the school' Cordelia Chase, who wore a skin tight cat costume, ordered from her seat across the table. "Your dirty fantasies wouldn't happen if you were the last guy on the planet let alone in this group."

"Oh yes, thank you for that." Replied Rupert Giles, the school librarian and undercover Watcher who was assigned to train Buffy in the ways of vampire slayage, as he exited his office. "Good to know I rate one of the girls, as it were."

"Don't worry Giles," Xander said, "you only don't count because it's the nature of a teenager to avoid thinking about a parental figure like that."

"Quite." The older man replied with a slight smile. "Mrs. Calendar? I suppose you got caught up in this too?"

"I did, I was Jean Grey as the Phoenix." The self-proclaimed 'techno-pagan' stated, causing Xander to quirk a metaphorical eyebrow in confusion, despite already being aware of this information. He had been dressed as Apocalypse, a mutant also from Marvel comics, a character who was ungodly powerful in many ways including telepathy. While in control of the teen's body he had done a broad scan of the area and had not found any other mutant, and though unlikely, it was possible that Jean had somehow blocked her mind from Apocalypse's detection. This would bear more looking into.

"So what happened?" He asked. "Why did we all become our costumes?"

"Ethan Rayne happened." The librarian answered. Ah, Xander thought, a name from Giles' past. Of course he couldn't show that he was aware of that fact, so he put a confused expression on his face.

"Sorry, but who's that?"

"He's the guy who owes me money." Cordelia complained while pointing out a wide tear in her costume, "There's no way that Party-town will give me my deposit back."

"He's the guy who sold us the costumes." Willow answered, ignoring the cheerleader's rant.

"The very same." Giles continued, "He is a Chaos mage of ill repute. He performed a spell turning everyone who bought their costumes from his shop into the characters they dressed as/ Fortunately, I was able to track him down and put an end to the effect. Speaking of which, where did you go after the spell ended?"

"The whole thing really freaked me out, being trapped in the back of my own head as someone else ran around in my body." he explained before slipping into a smoothly delivered lie, "I wanted out of the costume as quickly as I could, so I ran home and changed. Sorry for worrying you all."

"It is understandable, just next time please let us know that you are safe before running off."

Xander nodded. "I will."

"Yeah and next time don't leave us to take care of all those brats on our own." Cordelia demanded.

"Yes Queen C." Xander replied, his voice dripping with sarcasm. It surprised him how easy he found it to fall back into the pattern of verbal dueling with the snarky girl. "As you wish Queen C."

"Quite." The tweed wearing man muttered. "Mrs. Chase's issues aside, have you had any left-over side effects from tonight's madness?"

Over the years Xander had spent a lot of time thinking about this moment and knew that between Buffy's 'slay it first' mentality and how much Willow worried about him, there was no way he could tell them that he still had all the powers of the Celestial-technology enhanced mutant 'Apocalypse'. They'd want Giles to find a way to remove his abilities and all he had learned about magic over his long life told him it would probably kill him. At least Jessie would think it was cool and would probably be upset it hadn't happened to him as well.

"Nothing." Xander lied, smiling at his friends. "Just some vague memories... and a strange hankering for cheese."

"Why did you lie?" Jenny demanded later, pulling Xander aside after the group had broken up for the night.

"Sorry?" Xander asked with a look of confusion on his face.

"When they asked if you kept anything from Halloween you lied."

He quirked an eyebrow, "I did?"

"Yes!" the woman nearly cried. "I don't know what you dressed as, but I know that was you in the car. How did you do it? Was it a glamour? You made yourself look older. And who was the other man that saved me?"

"Okay... I have no idea what you are talking about." He stated with a chuckle. The computer teacher rolled her eyes.

"I know what I saw. I don't know why you lied to them, but you can tell me."

Xander's lips formed into his signature goofy grin. "Sorry Mrs. C, but there's nothing to tell."