The plan is relatively simple.
Both versions of Dick and both versions of Damian will stay in Bruce's home universe. Their versions of Dick and Damian will help the other versions of Dick and Damian to get comfortable and to know that they're safe, with assistance from Alfred, who is now in the Cave checking over the other-universe boys and tutting disapprovingly at how skinny they both are. Bruce can already see many hearty meals in the other-universe boys' future.
Bruce, Cass, Jason, and Tim will go to the other universe. They will bring the other Batman's body home to his own universe and figure out who there could be trusted with the corpse. They will gather any information they can about the other Dick and the other Damian, and they will come back to their home universe to discuss what they find with everyone.
It's a relatively simple plan, and it should go easily enough.
The fact that Bruce even thinks such a thing is probably already proof that it won't go as well as he hopes. Every universe seems to have some form of grudge for Bruce's plans, after all.
As Cass, Jason, and Tim say their good-byes, Bruce does the same, but he hesitates in front of Dick.
Dick grins, clearly sensing what Bruce is thinking. "We'll do fine!"
"This isn't easy for any of us," Bruce says carefully.
"I know," Dick says brightly. "It'll be fine. Dami, Alfred, and I will take care of each other, and we'll take care of Lil' Dickie and Lil' Dames."
"I do not think those nicknames will suffice," Damian huffs.
Dick gestures at his and Damian's counterparts, who are with Alfred in the med bay, and brightens his tone further. "But they're just so lil'!"
Bruce makes a note to himself to check in with all of his kids, but especially Dick and Damian, after all of this is done. Encountering their alternate selves from what appears to be a crueler universe is sure to leave difficulties in its wake.
"Ready?" Tim asks, coming up beside Bruce with the universe traveling device in his hands.
Bruce gives Dick another look, then he looks at Dick's counterpart.
The Talon has his hands on the other Damian's shoulders, clutching other-Damian close as Alfred looks the two of them over.
"Ready," Bruce answers, hefting the body bag of the other Batman. "Jason, Cass?"
Tim holds out the device as Jason and Cass come closer.
Bruce puts a hand on the device, Jason and Cass do the same, and then Tim twists a few knobs and pushes the button on top.
The Cave flickers and fades around them.
For a moment, everything is nothing. It's pitch black, but it's also pure white, but it's also neither of those things.
Then the Cave reappears, except it's clearly not the same Cave they're all used to.
For one thing, it's empty. No Alfred, no versions of Dick, no versions of Damian. It's the alternate Batman's Cave, and it seems to suit him.
The lights of the Cave are sharper but fewer, sending almost-too-bright beams around the caverns while leaving some areas draped in thick shadow. The med bay area looks smaller. The Batcomputer looks larger. There are no fluffy sweaters flung over chairs, no half-filled cups of cocoa waiting to spill, no discarded headphones lying around. All of the suits lined up in the uniform bay are Batman suits: no Nightwing, no Red Hood, no Red Robin nor Black Bat nor even Robin.
Bruce heads to the med bay and, when there isn't even a single cot in there, he carefully puts the body bag down on the floor. Then he joins Cass, Jason, and Tim in exploring the Cave.
"Something is really not right here," Tim says, poking around a stack of what look like laminated papers on the Batcomputer desk.
"No kidding," Jason says. He's facing the line of Batman suits. "A Batman without a family. Bizarre."
"No, I mean, look," Tim says, holding up one of the thick papers.
Bruce and Jason come to see.
"Is that-" Jason begins.
"Title: Joker," Bruce grimly reads aloud from the top of the sheet. "Status: Eliminated."
"Eliminated," Jason says almost inaudibly.
Bruce carefully puts a hand on Jason's shoulder.
Jason lets him.
"Yeah," Tim says, putting the paper carefully back into its stack. "Every profile in this stack is 'eliminated.' Most of the Rogues are here. A couple aren't, but I'm not sure if they're missing because they aren't Rogues or because they're not yet 'eliminated.'"
Jason mutters something despairing-sounding under his breath.
Bruce doesn't ask. If Jason wants them to hear it, he'll say it loud enough to be heard, probably more than loud enough.
"Batman," Cass calls from another portion of the Cave.
Bruce heads her way.
Cass is standing in front of a small kitchenette-like section. She's peering into a microwave, poking at something inside. "How long was the other Batman gone?"
Bruce blinks. "I think he said he'd been on the Talon's case for a week or so, with three days of that time being in our dimension."
Cass pulls the thing out of the microwave and shoves it in Bruce's direction. It's a frozen dinner, the kind people who didn't have an Alfred might eat for supper in front of a TV. It's cracked open slightly.
Bruce frowns. He steps closer and waves a hand through the air over it. His hand comes away warmed and slightly moistened. The TV dinner is still hot.
"Someone's here," Bruce announces loudly, taking a defensive position behind Cass.
Jason curses, and Tim sighs, both of them copying Bruce and Cass in squaring up back-to-back for better defense.
A batarang comes flying through the air. It comes from the shadows in front of the med bay. It comes in Bruce's direction.
Bruce doesn't dodge. He doesn't need to dodge.
The batarang clatters to the floor several feet away from him and slides about a foot closer at an angle that would keep it from being anywhere near hitting Bruce if it even got the right distance, then it stops fully.
Bruce frowns. He makes a few quick hand motions to Jason and Tim.
Jason and Tim split up toward either side of the med bay, while Bruce marches right toward the front of the med bay, Cass directly behind him.
Something makes a squeaking sound from the shadows in front of the med bay. A dark shape detaches from those shadows and scrambles into the med bay, sidling up beside and behind a cabinet.
Bruce halts mid-stride just before entering the med bay. He didn't get a long look at that scrambling shape, nor a particularly clear look, but…
"Black Bat," Bruce murmurs.
Cass steps up beside him.
He turns to look at her, not at the med bay, not at the body bag still on the floor, not at the space behind the cabinet where the dark shape is hiding. He turns almost fully to her, announcing with his movements that he's not going into the med bay.
"Terrified," Cass says quietly.
Bruce nods. He expected as much. He thinks for a moment. Then he takes a single step forward into the med bay, just enough that he's out of the shadows and into the lights, and he sinks to sit cross-legged on the floor.
After a moment, another batarang comes skittering in Bruce's direction, this time clearly coming from the dark shape behind the cabinet, this time with better aim and force.
The batarang hits Bruce's knee.
It bounces off awkwardly and clatters to the floor.
Bruce looks down at where the second batarang now sits, then he looks at the cabinet.
A sob comes from the dark shape behind the cabinet before cutting off into a muffled whine.
"Hi," Bruce says, making his tone as gentle as he can. "Would you mind coming out here? It's all right. We're not angry."
He waits a moment.
Nothing happens.
"I'd like to see you," Bruce adds. "It'd help me know how I can help you."
Still nothing happens.
"Please?" Bruce tries.
For some reason, that seems to be what does it.
The dark shape detaches from behind the cabinet and moves into the light.
Bruce's heart does a complicated leap-and-sink-at-the-same-time motion.
There weren't any Robin uniforms in the uniform bay.
But wearing a domino mask, with several bruises visible even from this angle and distance, shaking slightly with every step forward, there stands a kid.