Disclaimer: I don't own anything you recognise.
This story is a request that I got last night from multyfangirl20, enjoy!
Billy POV
It started when I was 8, not long after I joined the JL, Batman ran a background check on me as I'm sure he does with everyone he comes within site of and found out that I was a homeless 8-year-old. Then he dug deeper and realised he had known my mother. For a night away, and that I was his son not C.C Batson's.
And after running 5 DNA tests without me knowing about it he brought me back to Gotham and told me before getting custody of me.
Giving me a excitable big brother, a somewhat distant but still caring Dad and a brilliant sassy butler/grandfather. I got my family…..and a crazy amount of combat and bat-brain training that felt like it was trying to make me paranoid at times, (seriously I had to memorise multiple plans for taking down the Justice League, plus make my own including ones for taking down family.)
"How is your homework going Master William?" Alfred asks, bringing a glass of lemonade for me as I only got home an hour ago from fighting Ibac and Sabbac back in Fawcett City and need to get my homework done before school in the morning.
Seriously, two and a half years ago I was living in a subway, how did I end up here? "Almost done" I tell before taking the lemonade, "Thanks Alfred. You make the best homemade lemonade."
He smiles, "You flatter me si-" before he can finish he disappears.
"Alfred?" I jump up, putting my lemonade and homework down, where did he go? He just vanished into thin air. I take out my phone and call Dad, he doesn't answer, feeling more worried I call Dick.
"Billy" he answers, sounding relieved, "All the adults have disappeared."
"All of them?" I question, worriedly "Alfred just disappeared from in front of me, your saying its everywhere."
"Fraid so" he sighs.
"I'll be at Mt Justice in a few" I tell him, heading for the cave, (good thing Dad made me scan in both my voice prints and bodies otherwise there's no way I could get through the zeta now stuck as a kid.)
"No Billy" Dick says strongly, "If you go Cap you'll disappear too, and explaining kid you to the team would be too complicated right now. Stay in Gotham, do your homework and go to bed. We'll have them all back by the time you get up in the morning" he promises.
"You sure?" I frown, wanting to help.
"I'm sure" he confirms, "We got this Baby Bird, you just need to stay whelmed and do your homework" he hangs up.
I sit back down with a sigh, looking to my homework and finishing off the last two math questions then take out me tablet and start looking around online.
A lot of kids are freaking out, I do my best to reassure them the young heroes have this handled, and I do settle a lot of minds, for just being another faceless kid on the internet. Then Robin, Aqualad and Kid Flash make a big speech and I'm not needed for calming anymore.
I just about to sigh off and go to bed like Dick said when a message goes to the Gotham Elementary school student chat group.
SchoolSucks84: Oh my god! Check this out! A live streaming video appears next to the message, Trickster, a Flash villain attacking downtown Gotham with a gun shaped like a nose, that is shooting acid powerful enough to instantly destroy the buildings and everything else it hits.
"Shaz-" I cut myself off, no if I go cap I'll disappear, instead I call Wally, (this is one of his bad guys) but he doesn't pick up, so I try Dick who also doesn't pick up, they must be super busy with what's going on.
They won't answer in time to stop Trickster from causing even more property damage and possibly killing someone and I can't turn into cap.
But that doesn't mean I can do anything. I get up and go down to the cave, were I put on my costume Dad insists I wear it whenever I'm cap so if I somehow get turned back I'm still armoured, armed and my ID is protected, though I only remember to put it on half the time I go out as cap. Its dark red with white edging, with a dark gold utility belt, a dark red hooded cape, also with whit edging and a dark gold bat on my chest with lightning around the edges and a domino mask.
Once I've done a gear check and pushed down my nerves (I've never done the hero thing without my powers, sure I have all the bat-training but that's just training) I jump on Dick's motorbike and speed off to downtown.
I come to a stop, seeing a building falling over, the acid having destroyed the support beams. I jump off the bike, attaching my grapple to another building and pull the four teens were staring in shock at the building coming at them, I put them down clear of the building, which wrecked the street and Dick's bike, oops didn't stop early enough. I'll apologise to Dick later.
I grapple up to a rooftop and look around for Trickster, seeing him a block over melting another building, I run over and drop down, using a birdarang to knock the gun out of his hand before jumping down behind him.
"What?" he frowns looking at his hand before turning around, looking confused, "Your not Robin!"
"Nope" I agree, "Big brothers a little busy today so your suck with me."
He pouts, "I don't want some lame hero! I just wanna have my fun!"
"Your fun is causing a lot of damage and hurting people" I reply before moving forward, knocking the bag of marbles he was about to throw at me into a bin, were they explode.
"Your no fun!" he yells moving faster than should possible (I guess when you fight speedster you learn to be fast) and putting a rainbow hat with one of those silly fan things on my head, "Bye, bye!" he waves as the hat lifts me into the sky, going really high really fast.
I try to take it off, but its locked to my head. I take out my lock picks and work as fast as I can while it lifts me higher and higher into the sky.
By the time I get the lock undone I'm at skyscraper height in a part of the city that doesn't have any skyscrapers for me to grapple onto, if I take off the hat here I fall to my death, no real choice.
I take off the hat and yell "Shazam!" the lighting strikes and I fly under my own power, going back down, surprised to see grown-ups everywhere.
I fly down fast so no one sees me and to the edge of a large gathering of people outside of Gotham's Star Labs. The grown-ups are yelling at the police and Gordon is up on top of a car speaking "-est minds here and throughout the world are working on this and only this. Everything possible is being done to recover your…..our children. Violence will not get them back."
They think the kids are gone….its divided, one reality for the kids and one for the grown-ups and I can go between them, I need to find Dick and Dad!... after I stop Trickster, who is still on a rampage.
I fly to a alley near were Trickster is and say my word.
He has his gun back and is melting more buildings. Why is he doing this anyway? This isn't even his city. I knock it out of his hand again, his time using a low yield explosive (one that doesn't react with chemicals in acid) to destroy it.
"You again!" he pouts, "Let me have my fun!"
"Why?" I ask him, "This isn't what you normally do, why are you attacking Gotham?"
"….He said I wasn't good enough" he says after a few minutes, "I asked him to take me on as a apprentice and he said I was a cheap pathetic knock off who doesn't even kill! Which he kills is boring!"
"Joker" I realise, "Before this all stared you asked him to mentor you?"
"He's the best crime clown in the business" he replies, looking upset, fingering his pocket, likely looking another weapon "And he thinks I'm a loser!"
"The Joker is not someone you want to be" I tell him, "That man is 12 kinds of killer crazy. Trickster, you are not him and your not a killer, you know how I know that?"
"How?" he asks, moving his hand away from whatever he has in his pocket.
"You're a Rogue" I tell him, "Kid Flash told me once you guys have a saying, you don't kill, don't maim, don't hurt kids because…"
"Were villains not monsters" he finishes, looking a lot more calm.
"That's right" I nod, putting cuffs on him and taking his weapons, "When this is over I'll make sure you get transferred to Belle Reve, Colds there right now" I tell him, knowing from Wally Cold is like a Dad to Pied Piper and Tricksters.
He grins happily.
"Nice job" Barbara Gordon says, walking over to me. (She's Dick's best friend, he thinks she'll figure the Bats out within a year, I say 6 months.)
"Just helping out Miss Gordon" I reply, "What are you doing here?" I ask.
"Just helping out" she replies, "With all the adults gone the kids of cops are out in force trying to keep the city together" she looks a little worried.
I hand Trickster over to her, "And your leading them?" I guess.
"Yep" she nods, "So who are you?"
"Umm, Robins little brother. I'm just helping out while he's busy" I reply.
"Do you know anything?" she presses, still looking worried "About were my Da-all the adults are."
"They're okay" I tell her, "Looks like we go divided. They're on one Earth thinking we vanished like what we think here" speaking of I need to go tell the others that. "I need to go."
She nods, looking relieved. "Okay see you around."
I grapple to a rooftop and go the four blocks to the closes Zeta and go to Mt Justice.
I go to the planning room were the whole team plus Zatanna are gathered, "Robin!" I call running in, making everyone turn to me.
Dick looks to me, surprised "Baby Bird what are you doing here? I told you to stay home."
"You know this child Robin?" Aqualad asks looking to me.
"He's my little brother" Robin replies, sending me a look, "Who should be home in bed."
"You and Wally weren't answering me and Trickster was melting buildings in Gotham" I reply, crossing my own arms.
They both wince, "Oops did you…..?" Wally asks.
"I took care of it" I reply, "But that's not while I'm here. When I was fighting him I had to go cap and I found out I can go where the grown-ups are. Its like were divided into two worlds."
"Back up" Artemis puts a hand up, "What do you mean go cap?"
"I'm Captain Marvel" I reveal, much to everyone but Dick and Wally's surprise (those two are snickering about their reactions,) "I say the name of the Wizard and I turn into a grown-up."
"So, your 10, Captain Marvel and Batman's son" Superboy asks shaking his head.
"As much as I'm loving your faces" Dick cackles.
"And we are" Wally grins.
"We need to deal with this" Dick grins, "Marvel go to the grown-up side, tell Dad what's going on. We can use you as a messenger, so we can stay in contact with the other side."
"Got it" I agree before saying, "Shazam" the lighting appears and I'm standing in front of Batman and Zatara.
"Captain Marvel" Zatara blinks surprised, "How did you get here? Where have you been?"
"The other world" I tell him, "Its two different worlds, one for kids and one for grown-ups!" I tell them both, wanting to hug my Dad, but knowing the rules about what to do in costume.
"Is everyone alright?" Batman asks me.
"Yeah everyone's okay" I them.
After that we get to work, me relying information so we can attack at the same time on both sides.
It goes well, we win even, but we also lose when Zatara sacrifices himself to Fate to save his daughter. After everyone goes home to sleep and the next morning the League gets together for a big meeting over what happened.
"How is it you found a way to communicate between the worlds Batman?" Aquaman asks, looking to Dad.
"Ummm it was me" I raise my hand awkwardly, "I can turn into a grown-up. Which let me come to the other world and talk to Batman and Zatara" I can't help glancing at Zatara's seat which Dr Fate now occupies. What he did was so not cool, he should be in the League.
"You're a kid?" Hal blinks, surprised "How come we didn't know this? How old are you?"
"Ten" I admit, which leads to everyone talking over each other loudly, upset they let a ten-year-old in the League.
"Joining the League was his choice" Batman speaks, silencing the room with those six words. "Just as it was each of ours, his age doesn't change what we do or how well he has done his job, for the last three years, two of those as a member of the Justice League."
"He is a child" Wonder Woman protest, "How would he parents feel if we told them what their son has been doing? How we have put his life in danger?"
Everyone looks upset, thinking about putting little kids in life threating situations.
"I am fine with it" Batman tells the room, "I have trained both my sons and I know Robin and Marvel can handle themselves."
"He's your kid?" Flash stares surprised, "You're a bat?"
"You told me Billy had no interest in wearing a cape in Gotham" Superman speaks sending his friend a glare.
"He doesn't" Dad smirks, "Not in Gotham anyway."
Superman groans, "Bruce! I thought we agreed on honestly, no more word play loopholes!"
"I'll be honest with you when you start talking to your son" Dad replies.
"HE'S NOT MY SON!"
"Enough" I speak, making everyone quiet down, "I'm sorry I didn't tell everyone the truth, but I can handle it and I know what I'm doing."
John (one of the Green Lanterns rubs he's forehead tiredly, "I say we table this for the meeting about new members next month and focus on what happened last night."
Everyone goes back to talking about last night and Dad sends me a small smile, signing 'well said, son.'
I smile back.
ONE-SHOT.
