My first attempt at a crossover, so be nice. Set in my 'All's Fair' universe in the future, but can be read alone. Rogue has control of her powers and has Carole Danvers' as well (Ms Marvel). Oh, and Avalanche and Jean Grey are twins. But that's all you really need to know.

Chapter One

Underneath the streets of Jump City, the Teen Titans were gathered in a final farewell to their fallen team-mate/enemy, Terra.

The girl herself stood on a pedestal, arms spread wide, her mouth open in a silent scream, forever frozen in a prison of stone.

Starfire knelt and laid a bouquet of roses at her feet. "I'll miss you, Terra."

Raven nodded, her suspicions of Slade overriding her suspicions of Terra. "We'll be searching for a way to reverse the effects."

Robin glanced at Beast Boy, whose eyes were fixed on a plaque in his hands. "We'll bring her back."

"Someday." Cyborg finished.

Beast Boy fastened the plaque to the pedestal. "I'll never forget you, Terra."

The five stood for a few moments more, heads bowed in respect, then they turned and left the cave without looking back.

A small glint of sunlight filtered through, reflecting off the statue, catching the lovingly carved words. Terra. A Teen Titan. A True Friend.

The End…

…Or was it?

Almost as soon as the Titans were out of sight, two figures emerged from their hiding place. Both were obviously older than the teenage heroes, although the age-gap could vary depending on whether one judged by their appearance, which suggested several years, or the glint in their eyes, which implied at least a decade.

In reality, they were twenty-three and twenty-four, only eight years older than the Titans, but they were members of the X-Men, who were to the Titans what the Brotherhood of Evil was to the Hive Academy.

The young woman, a beautiful brunette with clear blue eyes and a stunning figure, casually brushed the dirt from her uniform, paying little attention to her surroundings, a vacant expression on her face as she conversed telepathically with her sister-in-law.

Her husband, also dark-haired, but with deep brown eyes that seemed to invite confidence, stood before Terra, observing her quietly.

Lance and Kitty Alvers – otherwise known as Avalanche and Shadowcat – had been married two years and had three beautiful children, Liam, Callie and Thomas.

They, along with the rest of the X-Men, knew about the Teen Titans, but all tended to leave the other team to it; they could easily handle themselves and the X-Men had their own lives, without bailing out anyone else.

However, when one of their old enemies, Mesmero, began showing up on Cerebro in Jump City, everyone began paying a little more attention.

They picked up only fleeting moments of telepathy and saw no reason to warn the other team just yet; in fact, they had been just about to forget the whole thing, when there was a sudden burst of telepathy, in the same vicinity as another mutant, which had caused them to start looking for anyone who may have been possessed.

Terra was the obvious choice, especially when she turned on the Titans, but there had never been an opportunity to jump in, especially with the power the girl wielded.

In the current situation, they had all the time in the world, even if the danger had been averted. Now all they had to do was explain everything to Terra.

"We should have brought Amara with us." Lance sighed.

"Look, we'll get her out." Kitty told him, breaking out of her reverie. "Anna's on her way down and she'll assess everything."

As if on cue, Anna LeBeau – better known as Rogue – flew through the tunnel and landed next to Lance. "Did a number on herself, didn't she?"

"Can you get her out?" Lance asked immediately.

"Lance, why are you so worried?" Kitty rolled her eyes. "I mean, I'm concerned, but…you've never met this girl; what is it?"

"I think she's Hayley." Lance whispered.

"Hayley?" Kitty repeated. "Your baby sister, Hayley? Hayley who was abducted from your front yard? That Hayley?"

"Yes, that Hayley." Lance confirmed.

Kitty sighed and joined him, taking his hand. "Lance, she can't be. Sara's a redhead; your dad had dark hair. Blonde hair is…"

"A recessive gene." Lance finished. "I know. But it fits, Kitten. Her age, her background. Her powers."

"Lance, her powers have nothing to do with it." Kitty disagreed. "Wanda hasn't got super-speed and Pietro can't hex people. You're not telekinetic and Jean can't make earthquakes. Paige isn't…"

"Alright, I get it." Lance interrupted. "I can dream, can't I? Besides, Tom had to get his eyes from somewhere; they're not yours."

Kitty opened her mouth to argue and hesitated. Her husband was right; their youngest child had been born with blue eyes, but not the shade that most babies were born with and not the colour of her own eyes. "Well…"

"Alright, you two," Anna cut in. "You know how important silence is at times like this."

"Sorry, Rogue." Kitty seized Lance's arm and dragged him out the way. As Anna closed her eyes and reached out telepathically, the couple settled down to wait.

And wait they did.

Nearly an hour had passed before Anna made a small triumphant noise. "There she is. It's okay, sugar, we'll have you out soon."

Lance got to his feet and helped his wife up as well, just as the stone cracked, the cracks glowed yellow and Terra collapsed to the floor, gasping for breath.

As Anna staggered back, exhausted by the effort, and Lance caught her arm, Kitty hurried to the girl's side, slipping her jacket off and wrapping it around her shaking form. "It's okay, hun; you're safe now." She bit back a gasp as Terra looked up, seeing in her eyes the same colour as her son's. "Lance, I think you might have been right."

"Right about what?" Terra asked shakily. "Who are you? What's going on?"

"First things first." Kitty told her. "My name's Kitty Alvers, or Shadowcat, if you prefer. I'm…"

"…third-in-command of the X-Men." Terra finished. "I've heard of you. You're going to take me in, aren't you?"

The question threw her. "Why would we do that? You're not the first person to get taken in by Mesmero and you certainly won't be the last."

"Mesmero? But…" Terra looked from her to Lance and Anna, who had joined them. "But it was Slade. I've never even heard of Mesmero!"

"Same person." Anna told her gently. "I'm Anna LeBeau, or Rogue, and this is Lance Alvers, Avalanche. You're not in any trouble; we just want to clear some things up."

"First of all, if we left you here, where would you go?" Kitty asked. "Back to the Titans?"

Terra laughed humourlessly. "After all that? I can't face them after that. No, I'd probably go back to wandering aimlessly."

"Secondly," Lance continued, "do you want help controlling your powers?"

"Do I want…?" Terra trailed off. Unless the X-Men caught your powers when they first emerged, they very rarely approached mutants; there was something else going on. "Are you offering me a place?"

"We are." Anna nodded.

"Why me?" Terra questioned.

"Well, you're very powerful." Kitty told her. "Although I'm sure you know that. Without proper control…well, it could be dangerous. You saw what happened earlier."

"But there is another reason." Lance added. "Do you have any knowledge of your parents?"

"My…My parents?" Terra frowned. "No…No, I grew up with 'Uncle Frank' and…" She shuddered violently. "I didn't run away for nothing. I assume he wasn't my real uncle."

Anna reached out to her. "Do you mind if I probe your memories? We have a theory."

"No, go ahead." Terra told her.

Anna closed her eyes again and Lance and Kitty watched with baited breath, unsure of the outcome, not wanting, not daring to hope.

Finally, Anna opened her eyes and smiled. "Well, well. Hayley Alvers, we've found you at last."

AN: Should I continue this or leave it as a one-shot? Review and tell me what you think!