Notes: I was asked, by anonymous comment, if I intended to keep this family or if I'd make a romance. The fact is, I'm not sure myself yet. If there is a romance, please be assured it will be cross-world Jason/Bruce; so no paternal nor fraternal figure, except in a very messed up way. (But then, Jason is kind of messed up). In any case, I'll add a warning at the top of the chapter if I ever switch to romance :)

Finnland93: thank you for your review! I hope this answered your question, however opaquely. In any case, I hope you'll like this chapter!

Chapter 4

Jason followed Bruce to the top of the nearest building, then across a few streets, getting away from Crime alley. Not that he intended to follow him like a good little pup; but that place meant too much for both of them for Jason to argue there. Besides, he needed time to think.

Jason Wayne, brother of Bruce Wayne. It was just so weird.

This younger Bruce hadn't said where they were heading; maybe he hadn't decided yet, or he simply headed to the Cave by default. The manor was well outside Gotham, though; which meant their current target would actually be…

Jason snorted when he spotted the Batmobile in a street a few blocks away. Bruce was so predictable.

He glanced at the silent figure moving ahead of him in the shadows, its movements both familiar and foreign. This Bruce was young, barely older than Jason. Alright, maybe five years or so older, but they probably had spent about the same amount of time in the streets.

Jason smirked.

His curved knife sliced Batman's line neatly while it was just about to tense. Jason saw his eyes widen as his momentum sent him straight to a wall. Of course, he opened the cape, slowing himself down – which allowed Jason to crash on his side, feet first.

Bruce let go the cape, trying to grab Jason's ankle for them to fall together. Jason stabbed his knife between two bricks in order to change his direction, dodging his hand, and finding himself on top once more. Two batarang came at his head; he pushed against the wall to avoid them, and threw one of his own to force Bruce to move instead than waiting for him once he'd hit the ground.

Jason landed a second later, rolling on the dirty pavement to get closer to his opponent. The alley where they'd fallen was narrow enough to impediment Bruce's movements – the cape couldn't always be an advantage. Bruce's best chance was to keep enough distance to aim his batarangs; he was better with them than Jason, who favored guns as long-range weapon. Better not bring those to this fight.

Jason reached Bruce before he had the time to retreat, aiming for the knees, waist, and other junctions where the armor would be more vulnerable. Bruce took the first punch, parried the second; then, instead of taking advantage of his bulk to endure a few blows so he could enter Jason's guard, he started dodging.

Jason blinked. Bruce's movements were fluids, sharper than expected. Jumping, he pushed against the wall to fuel his movement, gracefully jumping over Jason's head to land on the other side of the alley, throwing a few batarangs in the process.

Jason felt a laugh bubble his way to his throat and let it, delighted. The alley still gave him an advantage, yet he found himself firing his line to go back to the roof, where Bruce would be able to fight with all his skill. He wanted to see how good he was; damn the consequences.

Bruce thankfully followed, either too frustrated or too worried to disappear in the shadows to sneak on him instead. Jason was waiting for him. He kicked first, trying to trip him, then to grab his cape as Bruce jumped over his head again. To his surprise, Bruce let go of it, and the thing draped itself around Jason. He dodged a blow to his jaw, cursing as he had to cut himself free. Thankfully, he still had his kriss – he sure wouldn't have abandoned that knife on the top of a building.

They circled each other, Jason grinning, Bruce trying to keep a straight face. But Jason could see it in him too, the adrenaline, the joy to face a valuable opponent.

He tried not to wonder if Bruce had been like that, back when Dick met him. How would have it been, not to be the first but to meet a younger, sharper Bruce?

Pushing the thoughts away, Jason attacked once more, refraining from using his knife. Bruce interpreted it correctly as a wish to spar as opposed as to maim, and finally allowed his lips to curve slightly. They clashed at the middle of the rooftop, exchanging blows, each movement meeting its perfect counter, so fluid it could have been a choreography.

Fuck, this felt good.

Then Bruce's fist crashed on Jason's face, while Jason's got him right in the stomach, and they jumped backward to take a break. Their smiles had grown into grins.

Jason shrugged, and offered him his hand. Bruce blinked, then took it, shaking it with some dose of respect.

"So," Jason said eventually. "The Cave?"

Bruce nodded, always the chatterbox; and they both dropped to the Batmobile.

###

Talia had always been a remarkable woman. Strong-willed; self-confident; and skilled enough to have beaten Bruce and Jason both back when they'd arrived at the League of Shadows to request Ra's al Ghul's guidance.

She had managed to keep the upper hand ever after they'd become enough of a challenge to win their fights from time to time. It wasn't just the skill. She knew her worth; and she knew they knew. Jason admitted freely that he had been fascinated.

Few women could pull this off. Few people, women, men or alien.

Of course, he couldn't have let anything happen between them, not knowing that any attempt at seduction would have been commanded by Ra's. But still, there had been an intensity to their fights, and he'd thought – he'd known – that there had been something more. Something that had grown stronger as he refused her advances.

Then Bruce had given in to her, the fool, and that had ended it.

Jason would have strangled him. Not because he'd had Talia – it wasn't the first time Bruce had won the girl, and it wouldn't be the last – but because he'd done so without thinking about the consequences.

Those had materialized only years later, though, when they'd found Damian at their doorstep.

The Damian from this world looked only a couple of years older than the one he considered his godson. It was fascinating to spot the similarities, the differences. Here, too, the kid was obviously Bruce's. He looked more comfortable in this Cave than his godson was in theirs, but considering the age difference, he'd probably been living longer with the Wayne part of his family.

Jason hadn't seen him interact with anyone else than Bruce and Alfred – they'd banned their other allies from the Cave since he'd arrived – but Damian was obviously at ease with the two men.

Apparently, things were different with the young woman who'd just entered the Cave. She looked dangerous enough for Jason to directly have thought of Talia, though she lacked the Demon's daughter's sensuality.

Damian tensed slightly as she approached – only slightly, which spoke volumes about how much he trusted her. An assassin didn't trust other assassins, especially ones skilled enough to be a threat.

Yet he let her close enough to be within her reach. In return, diplomatically, the young woman allowed him to enter in her personal space, where he would be able to fight back.

Jason raised an eyebrow, not bothering to hide his surprise. Of course, this Bruce had trained with the League as well; and of course he was surrounded by skilled people. But this woman was different. She wasn't merely dangerous; she was lethal. It showed in her every movement, in how she stood, in the way her eyes moved around.

Slowly, Jason felt himself smile. How not to be glad about meeting someone that interesting?

To his surprise, Bruce guided her to him, Damian staying a few paces behind. They stopped in front of his cell, and Jason felt her focus on him. Her attention didn't feel as oppressing as he would have thought. It was almost… gentle? Curious, not aggressive.

"Jason, this is Cassandra. She and I work together. Cassandra, this is a Jason from another Earth. I would like you to assess him."

Jason blinked. Assess? Was she a meta? He reevaluated her from 'dangerous' to 'unsafe to be around' in the blink of an eye, his instincts screaming him not to allow her near him. Yet the young girl merely blinked at Bruce, perplexed, before coming closer to the cell's transparent door. Jason muzzled his instincts, smiling at her instead of retreating.

She observed him for some time. He paid close attention to his thoughts, but didn't feel any mental tug. Either she was better than anyone he knew or she wasn't a mind reader.

After a time, she scowled, glancing at Bruce. He tilted his head. She seemed to understand his silent question and waved at the cell's door.

"I need to go inside." Then she frowned. "No. Him, outside."

Jason didn't let his face show his perplexity at the lack of fluidity in her speech pattern. Maybe English wasn't her native language? She did seem to have Asian origins, but considering how everyone in the States came from somewhere else, one to ten generations back, he had simply assumed she was from around Gotham. Stupid of him, considering her level of skill.

His surprise increased as Bruce nodded to her request. He did, however, wave at Damian to have the boy come closer to him. Then the door slid open.

Jason blinked, looking at the girl. She took a few steps back, giving him space. He fought back the need to purse his lips, offering her a smile instead, and stepped out.

He quirked an eyebrow.

"What now?"

Her eyes sparkled briefly – and she rushed forward, Jason only dodging by pure instinct. What the… She might be lethal, Jason didn't want to hurt her! Lethal or not, she was a kid. He retreated on the left, away from Bruce and Damian, not to find himself walking back in his cell. She was too quick for him to just move away, though; lighter than him, more agile, and too precise to be dismissed.

Damn. She was forcing his hand, here. But then, maybe that was the point.

So Jason stopped dodging and struck, making sure never to pause his movements even though touching her proved to be challenging. He only need to hit her once. However trained, she just wasn't bulky enough to take many of his blows without serious damage.

Not that he wanted to inflict any; he dared hoping that the pain would be enough. Finally, he caught her, a punch in the stomach that sent her stumbling back, certainly hard enough to have emptied her lungs. Yet she came back at him, not even blinking.

Alright, hoping pain would stop her had been naive. But she wasn't a criminal, and she was too good for him to fight her without giving everything, damn her.

He fell back on the defensive. She might be a lightweight, but he wasn't; as long as he kept her from landing a nerve strike, he should stay able to fight.

Or he could just unbalance her, though that would be difficult. Yet he switched to aikido, a martial art he rarely used but which had its advantages, and took her by surprise. She saw his movement change, but was already too caught in her own momentum to backpedal, and he managed to enhance her own movement and locked her in a painful wrist key.

"Don't try to move away, this test isn't worth getting a bone broken," he warned.

She pouted, then grinned, then nodded. He released her, absentmindedly parrying her kick and a subsequent blow, because of course she would check if he was still on his guard despite their little match being finished.

"Yes, I do know fights don't end when one says uncle in real life, kiddo."

Her grin widened as she nodded at him. She walked back to Bruce, light on her feet.

"I like him," she declared.

Bruce frowned.

"I wasn't talking about his strength."

She shook her head, and replicated slowly a few of Jason's prior moves, when he'd retreated instead of attacking after his first blow, then when he'd switched to aikido's reactive moves.

"He cares," she declared, her tone final.

Bruce looked at her insistently, but she didn't back off. Eventually, he moved back to the console and pushed a button, closing the cell's door.

Jason blinked. Apparently, he'd just won some amount of trust. Dumbfounded, he eyed Cassandra – who winked at him. She waved at him to get closer, her other hand pointing at the mats nearby, then closing into a fist.

"You want to spar?" Jason tried.

Her grin turned sharper. Jason observed her. She had just given an assessment after a few passes, one Bruce trusted. She had fought with movements even more natural than Dick's, and a strength well hidden in this young body of hers. More than that, she had seemed to anticipate most of his own moves, only surprised when he'd changed pattern in a last minute decision.

She could read him, he realized. That's why Bruce trusted her opinion so much. He had labeled Jason as a liar – which, admittedly, he kind of was; being COO of a company like Wayne ent. did that to a guy – and had hence decided to seek the advice of someone who wouldn't listen this his words.

Which also meant she didn't merely invite him to spar; but to converse.

Jason relaxed, letting his eyes soften, and bowed slightly for her to lead the way. She almost blushed at that, pointing an accusing finger at him. Five minutes later, she was punching her arguments pretty clearly, while he silently laughed at her.

###

Notes: Hope you guys still like this :) Harder chapter to write with all the fighting; but I managed eventually XD

And thank you all for your encouragements, it helps a lot :)