All recognizable characters belong to their respective owners (Cartoon Network, Simon R Green). For a prompt on YJ_Anon_Meme.

When she finds him, he's curled into a ball small as he can get. The mindscape is dim, a dark room she doesn't recognize. He's hiding in a corner.

There's another man in the room, older, with brown hair and a mustache. He's moving, but ever so slowly. Time stretches out, one of the man's steps taking minutes. Except there's no time here.

She'll count in heartbeats, then.

"Wally?" she whispers, not wanting to startle him. "Kid Flash?"

He flinches. She covers the distance between them—one heartbeat, two—and gently touches his shoulder.

He makes a noise, like a choked sob.

"It's okay," she murmurs, settling herself on the ground, draped over his back. "It'll be okay."

He says "No, it won't," to his thighs. He lifts his head and rests his chin on his pulled-in knees. "No," he says more clearly. "It won't be okay."

He won't look at her, so she does him the courtesy of not trying to get him to. "It's simple theoretical physics," he says bitterly. "Uncle Barry's hit the right frequency to dimension-hop before. Do you know what'll happen if I don't—if I can't slow down?" Down goes his head again, and she strains to hear. "Molecules vibrate at speed creates friction makes energy that builds up and it's gotta go somewhere, and I don't wanna blow up, don't wanna die don't wanna take you take anyone with me don't wanna leave—"

And now she understands the molasses-moving man.

"Shhh," she soothes, and floats around to give him something to cling to. "See, you're fine. Listen—" and she has an idea. "Listen here. Hear my heartbeat?"

He sniffs, hangs his head closer, then freezes.

"It...It's normal," he says, wonder heavy in his voice. "It's at normal—I'm at normal speed!"

He's up and spinning her around before she can blink. His eyes are still red and puffy, but she laughs with him, and claps when he lets go.

It takes him a while to settle down. "What is this? Where are we?"

"A mindscape," she says. "He shoved out right out of reality and into our minds."

"How did he even...? I mean, who is this guy?"

She frowns. "I don't know, but I've never felt anything like him before. Robin started to say something about it, I think, but..." She made a gesture that Wally interpreted as "he got interrupted when we fell out of the real world and into our own."

"We should find him, then," he says, then stops. He shoots her a look. "Uh, about..."

"Our enemy has considerable mental manipulation skill," she saves him. "He's called up all our worst fears. So we should hurry up and find the others."

She doesn't add, before they break.

And he shudders, because he's not all back together yet, no matter what he pretends. If this third teammate has also been an illusion, he just might have broken himself.

Wally takes a deep breath, and M'gann opens the door.

They step out, and fall. Wally feels hands under his armpits, and M'gann lifts them out of the hole and sets him gently down on his feet. He glances back at the pit behind him, and the door behind that.

There are walls to the left and to the right. There are stone walls, wood, walls, walls that aren't walls, and this one pink, fleshy bit, that almost seems to be breathing.

And in these walls, there are doors. So very many doors, black and brown and metal and crystal and bleeding and broken and shiny and alluring and one or two that slide away from the corner of his eyes, that may or may not actually be there.

"What is this?" he asks quietly. "Where are we?"

"It's the Place-Between," M'gann says, voice equally hushed. "I don't normally come here. But I can't fly through the aether and carry another person. Sorry."

Wally looks around and shivers. "The doors...?"

She nods. "Minds. The doors reflect the interior."

"I don't suppose you know what our teammates' doors look like?"

"I don't normally come here," she repeats, and looks around. Wally can sympathize with that. "But I can hear a sound, a voice, one that shouldn't be here...

"I don't like it," she whispers.

"Make you a deal," Wally says, faux-cheerful, and winces at how his voice echoes from stone to wood to glass, and on and on into the dark. "You point the way to the creepy voice and I'll open all the creepy doors."

So together they wander, M'gann looking beyond the world beyond, and Wally pausing a second at each door, waiting for a spark, a hint a clue that he knows the person behind the door. It doesn't come.

...

To be continued