Morty knows he shouldn't be screwing around with multidimensional shit. It's dangerous, it's impractical, it's blah blah blah. But it's a potential key to unlimited energy, how does nobody see that? He's built a dimensional siphon (it kind of looks like a cardboard box with a funnel and a TI-84 taped to it, but it damn well works), keyed in the dimensional coordinates to a random plane, and by God he's going to use it.
He flips the switch and waits for the energy bar to fill up.
It does! It fills up very rapidly. Then it explodes, along with the box. There's rather more smoke than there should be, and once the smoke clears someone is standing there.
"Whoops?" Morty says faintly.
"It's high-percentage, but Ariel's about as powerful as Redoubt was and nobody's throwing her in a black cell."
"Uh, oubliette? It's where you put really bad supervillains you can't kill and people whose powers are uncontrollable and apocalyptic."
"Time-freezing magic, I think? It's not exactly public record, I just know that's where they put Maelstrom and Tearaway and stuff like that."
“Maelstrom and Tearaway were big-time mutant terrorists back in the 50s. Maelstrom was a psi and a blaster, Tearaway ate people. They were seriously bad news. Then they got captured by the Mystic Six and tossed in a black cell, where to the best of my knowledge they remain to this day.”
"Are there a lot of movies about something going wrong with the black cells and plucky heroes having to defeat all the villains of yesteryear?"
“Thrillers prefer making up their own mutant villains. Less chance of survivors’ advocacy groups boycotting you.”
"That makes sense." Her Kharoline frybread is all gone. "I think I'm due for powers testing soon, but it was nice to meet you all."
He smiles. "Good to meet you. Let's see, we're going to be in Lab E - just follow me."
They pass by a couple of different labs on their way to Lab E, including one with a treadmill on the ceiling. Lab E turns out to be a medium-sized room containing weights, a computer, and a more conventionally floorbound treadmill. It also contains a middle-aged gentleman in a tweed coat, who waves as they enter. "Hello! I'm Louis - I'm the psychic test."
"Okay. It's a pity I can't just submit my application for the subtle arts major here."
"I assume this would not be your job if you were not pretty comfy with it," she remarks to Dr. Duncan, "but when I signed up for a therapy major I took an oath to be scrupulous about consent and so on, so if you wouldn't mind confirming verbally..."
"Alrighty." She peers at Dr. Duncan's brain, hand to her temple to politely signal that she's doing so in her local parlance.