The kid trembles but keeps walking forward, getting just within Bruce's arm's reach before stopping there.
Bruce considers the kid and tries to figure out what Bruce knows. The kid is of an indeterminate gender, evidently young enough for the more usual gender markers of puberty and onward to not yet be present. They're visibly banged up: a bruise on their lower jaw, another bruise on their forehead, a third bruise around a cut peeking out from their hair by their ear, and a scabbed-over split lip, and that's just what Bruce can see. Their clothes are dark and shapeless but cover their body except for their head, neck, and face, which has the aforementioned domino mask. The domino is barely starting to peel away, clearly not sized for such a small face.
Bruce's heart hurts for this kid. He wants to think the best of the other Batman, wants to think that the other Batman rescued this kid recently, wants to think the other Batman is trying to do good by the kid.
But he can't. For one thing, the other Batman has been gone from this dimension for at least three days, and this kid has apparently been just… Left here. Wounded. Alone. Terrified.
To be fair, though, the terrified part might be Bruce's own fault, given the way the kid's head keeps turning toward the body bag over in the corner before jerking back to face Bruce himself.
"Hi there," Bruce says quietly, still sitting cross-legged on the floor.
The kid says nothing, just swallows hard enough to be audible.
"I'm from another dimension," Bruce says. "Do you know about other dimensions?"
The kid still says nothing. They waver on their feet.
"Okay," Bruce says, taking a mental step back. "Can you understand me?"
The kid hesitates.
Bruce is just moving his hands up to try ASL and running through a mental list of what other languages he can try when the kid slowly, reluctantly nods. They're chewing on their split lip, which looks on the verge of starting to bleed.
"Good," Bruce says. "I'm glad. I don't want you to be scared or confused."
The kid huffs out a breath that almost sounds like a laugh. Immediately, they hunch up, shoulders rising to near their ears, arms wrapping around themself.
"It's okay," Bruce soothes. "It looks like you've got quite the scrapes on your face there. I don't want you to be scared or confused, but I don't want you to be hurt either. Would it be okay if I or one of my friends helped you out? We'd really like to help you."
The kid licks their lips, the split lip now sluggishly oozing blood. Quietly, they say, "I don't want to bother you."
"No bother," Bruce promises. "In fact, it would bother me more to leave you hurting."
The kid nods more sharply than necessary. "Understood."
"Okay," Bruce says. "Do you want me to help you, or one of my friends?"
At that, Bruce hears the footsteps of Cass, Jason, and Tim getting closer.
The kid makes a jerking motion back, but they step forward again immediately and say, "Whatever you'd prefer."
Bruce thinks for a moment, turning and trailing his gaze over his three kids behind him. Bruce himself is Batman, and he can easily cut an intimidating figure, likely even more so to this child who likely had negative experiences with this universe's Batman. That rules himself out for the kid's comfort. Jason is muscular and tall too, with an unfeeling-looking helmet. Granted, he can take the helmet off, but Bruce isn't sure that'll help much. Tim and Cass both have the advantage of being shorter and slimmer. Cass is female, which can mean she's "safer" in many victims' eyes, but Tim is more experienced with tending to others' first aid. Bruce waves Tim and Cass closer.
"Would you rather have Red Robin help you," Bruce says, motioning at Tim, then at Cass, "Or Black Bat?"
"Whatever you prefer," the kid repeats, sounding resigned.
Bruce holds back a sigh. Should he offer more physical safety or emotional safety? He'll go with physical to start with. "Red Robin, if you would help?"
"Sure," Tim says, and he moves toward a chair in one corner of the small med bay, waving at the kid. "What do you say we get you looked over, huh?"
The kid follows him without a fuss.
Honestly, Bruce would almost prefer a fuss from the kid. He's growing more and more concerned about what they've been through.
Cass lays a hand on Bruce's shoulder. "Okay?"
Bruce nods, mostly to himself, and he stands up. "Okay. Let's keep investigating."
This dimension's Batcomputer has quite the security system, much more severe than his own, Bruce admits ruefully, shaking the pain of an electric shock out of his fingers.
"Why would the guy do that?" Jason says, sounding frustrated. He's facing the Batcomputer with tension in his shoulders. (He startled more visibly than Bruce did at the zapping shock to Bruce's hand.) "I mean, the passcodes are obviously real strong if you're not in yet, B. It seems like a big inconvenience if he ever got his own passcodes wrong, which you know, everybody does sometimes. And if somebody's in the Cave trying to hack the Batcomputer, they've gotten past a bunch of powerful security systems already to get in here, and an electric shock isn't gonna do much else to them."
Bruce nods slowly, deep in similar thoughts. Then he frowns, the most likely cause dawning on him. "Unless that somebody didn't need to go past the security systems and was already in the Cave."
Jason curses and turns toward the med bay as he sees what Bruce is implying. "He put that in against the kid?"
"Most likely," Bruce says grimly, then huffs and jerks back as another attempt at hacking the Batcomputer shocks his hand again.
Jason curses again.
"Batman," Cass says from a good distance behind him.
"Yes?" Bruce says, eyeing the Batcomputer controls. Maybe if he-
"That's not working," Cass says frankly.
"I know," Bruce admits. "But it's our best bet at finding out more about this Batman and this world."
"What's second-best?" Cass asks.
Bruce pauses. That's fair. "Going out into this world ourselves and seeing what we can find that way."
Cass hums. "How about both?"
"'Both' sounds good," Jason says. "The sooner we can get done with this wreck of a universe, the better."
Bruce hesitates. "I'm not sure we should split up."
"So we'll stick together," Jason says. "Black Bat and I'll go investigate out there, and you and Red Robin can keep working in here."
"Buddy system," Cass says over-solemnly.
"Buddy system," Jason agrees, also exaggerating how serious he sounds.
In most other situations, Bruce might chuckle at that, but this is too much. Still, it's a fair idea. "You'll stick together the entire time?"
"'Course," Jason says.
"Yes," Cass agrees.
Bruce sighs. "All right. At the first sign of trouble, comm for help and come back."
Jason gives two thumbs-up signs and heads for where the vehicle bay is in their own universe, Cass right behind him.
Bruce turns back to the Batcomputer and keeps trying.
After a few moments, Tim calls from the med bay, "Batman?"
"Yes?" Bruce calls back.
"You'll want to see this," Tim says frankly.
Already dreading whatever "this" is, Bruce gets up and heads to the med bay.