Author's Notes: Billy and Cassie have never interacted in canon. I feel this needs to be remedied.
Edit 1 April: Slightly edited due to information from a new Greg Weisman interview. Because of course he waits until I've got the story out before giving details that Joss me.
"Recognized: Billy Batson, A05."
"Hey guys! I'm here for...oh, hey. Who are you?"
"Oh, um—I'm Cassie. I mean, Wonder Girl, Wonder Woman's new sidekick. I just joined the Team."
"Oh, cool! I was wondering if she would ever pull a Batman and get another sidekick, heh. I'm Billy, by the way. I'm from the Justice League."
"Um…you sure? Because I don't think I've ever seen someone like you on the news before."
"You don't think so? Here, back up a little."
"Why?"
"Just take a step back, give me some room…okay, check this out. SHAZAM!"
BOOM!
"Ah! You're—you're Captain Marvel! Oh my gosh, that is so cool! With the lightning and—wow!"
"I know, right?"
"So like, one of your powers is turning into a teenager?"
"No, no—I'm already a teenager. One of my powers is turning into an adult."
"And they actually let you in the Justice League? That is so not fair! I'm applying for membership."
"Heh, well, I sort of didn't tell them that when they first let me join; they almost kicked me out when they found out. So how old are you, anyway?"
"Fourteen."
"Wow, really? You look older."
"Ha, you should talk!"
"Ha-ha!"
"Ha-ha!"
"Okay, I guess I walked right into that one, didn't I? Heh. I'm fifteen, by the way. It's weird, back when I started I was young even by the Team's standard!"
"That's right, you've been a hero since I was, like, in first grade or something."
"Yeah, I started when I was seven."
"Oh my gosh, you were fighting crime before I took the training wheels off my bike."
"Ha-ha! So you're Wonder Woman's new sidekick, huh? Are you, like, an Amazon or something?"
"Oh, no. But I have superpowers and stuff! It's kind of a long story. Basically, I just found out my dad is Zeus— "
"Hey, some of my powers come from Zeus too!"
"Cool! Wait, does that mean we're like…related or something?'
"Uh, I don't think so. I'm just a normal human. I mean, I was born normal, but then I got my powers from a wizard."
"…Seriously?"
"Uh, yeah?"
"So what, you just met a wizard walking down the street and he gave you superpowers?"
"Heh, kind of. See, I found this magic subway and—"
"A magic subway? Let me guess, it connects at Station 9 ¾?"
"Hey, your dad is Zeus and you're calling my origin story ridiculous?"
"Ha, okay, I guess I can't argue with that. Man, I can't even believe I'm talking to the real Captain Marvel! You're like, one of my favorites. Not quite as much as Wonder Woman, but close."
"Heh, thanks. I used to feel the same way—one day I'm watching Superman on the news and then suddenly he's inviting me to the Justice League!"
"Exactly!"
"So, you enjoying the new hero gig?"
"Well, it's like—practically my first day. I mean, unless you count me helping rescue my mom from supervillains. It was a whole big thing."
"Oh, your mom was that archaeologist? I heard about that from Wally. Anyway, I'm sure you'll love being a hero."
"I hope so. I'm kinda nervous. I've only been at this for about a week and already Wonder Woman is really pushing me hard."
"Yeah, Batman used to treat me the same way. You know, back when I was a rookie. And it's a lot of work, you know, and sometimes you get mind-controlled or kidnapped by aliens and stuff. But it's also really fun. You get to go around, saving people and beating up bad guys and stopping natural disasters and everything. Plus sometimes it gives you an excuse to get out of school!"
"Oh my gosh, the first time that happens, I'm totally getting Nightwing to write me a note."
"HA! …So, what kind of superpowers do you have, anyway?"
"Well, I can fly, and do that whole bullet thing with my bracelets, and the other day I punched through an iron door."
"I have all those same powers! Well, I'm not sure about the bracelet thing, but I'm super-fast. But I also have wisdom, stamina, bravery…and I can punch through steel."
"Oh, what's that? The Big Red Cheese thinks he's stronger than me? You wanna take this to the training area, bub?"
"Uh, I'm actually not allowed to. Last time I trained with a new recruit I put Tempest in the hospital. Ooh, I have a better idea! You can fly super-fast, right?"
"Yeah?"
"Challenge you to a race around Happy Harbor. Last one back to the Cave has to buy the winner ice cream!"
"Ha, you're on! Now let's see, this place is so big, where was that exit?"
"I know where it is. Follow me!"
"Alright! But just for the record, I'm gonna make you pay for all thirty-two flavors!"
"Ha, we'll see!"
"Ha-ha!"
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"Hmm, she's not here either. Oh, hey, Gar, do you have any idea where Cassie went? She and I were supposed to start a training session at three."
"Um, she was here a minute ago. And hey, wasn't Billy supposed to come over today?"