Amy hands over a small piece of tech, salvaged from the computer. "This is for command. Something easily yanked by someone who knows how." 

She leads them back downstairs, using the floor plan to locate the secret elevator. Once she does, she presses the V on the Vault-tec, and the wall slides neatly away. "Nice to see some things still work."

Sarge and the bot crew follow her in. "This thing is a choke point if anything is still alive down there..."

Luckily for them, the elevator is a cargo one, built for bringing supplies up and down, though how they did that and kept it secret is anyone's guess.

"Good point. Try to stay on either side of the doors when they open. Hopefully we'll just find relics down there," Amy says as she pushes the one button, marked L-1.

The elevator shudders, then closes, taking them down below.

Once the elevator stops, Amy presses herself against the wall, bracing herself. The doors ding, a metallic voice announces "Floor Negative One", and then the elevator opens. 

Nothing. 

Amy pokes her head out, but can see or hear no enemies. "All right. Fan out. There could be anything down here."

"Stay frosty, boys. Nobody move without someone covering you."

As they move around the room, there's several scraping noises, as if something in here is pushing furniture out of its way.

Edward whimpers.

Bots point guns at any sounds but refrain from talking or shooting.

Amy shines her torch behind every shadow, trying to find the source of the sound. 

It seems to be coming from the wall to the right, heading closer all the while. If it's a feral, she needs to be ready.

It is not a feral ghoul. 

A half-finished synth drags itself across the floor, head jolting back and forth, wires inside the metal casing sparking.

SYNTH! Open fire!

"WAIT! Wait, wait!" Amy yells. "We want it intact for command!"

...Fine, cease fire. Flamethrower bot whacks a wall frustratedly and puts out his pilot light.

Amy goes through her pack (Edward lowers himself a little so she can reach) and pulls out a small blue energy cell. She attaches it to her pistol, lets it integrate into the systems, and then fires once into the synth's head. It goes motionless, head hitting the concrete floor with a clang.

"All right. Someone grab that, and we'll start heading further in."

Once one of the bots has the synth, Amy starts heading further down the row, the rest of the bots spreading out in the room. It seems to have a similar layout to the office floor, but much larger, and half the room is empty except for a few glass cells. Amy inspects one, and finds some sort of residue at the bottom. She can't tell exactly what it is, but it makes her uneasy. It makes her wonder if they were used to test the experiments that they would eventually inflict on Vaults.

She backs away, shoving that thought aside. Nothing she can do about that for now.

Amy heads back to the rows of computers, sliding into the seat in front of a random one. She boots it up, and plugs in her Pip-boy.

From there, it's a simple case of hacking through security to get to the files. She blanches at the list of Vaults, there are so many. She also knows that most of these will not be 'control' vaults, left to just live, survive. Most of them, the much larger percent will have tortured their inhabitants. There's a Vault-tec mug on the desk.

Amy picks it up, stands, and throws it as hard and as far as she can, and feels better for hearing it smash.

She then gets to work narrowing down the list of Vaults that could contain the GECK.

Well, there's nothing for the bots to shoot. Nick is looking through their cameras over her shoulder, though.

His voice comes through one. "Evil sods. Selling tickets wasn't enough, that had to go back on it and do science, too... As if it was even going to matter after the bombs fell."

"There's a theory amongst us who lived Before that it was Vault-tec that started the bombing. So that they would definitely get their test subjects, no ifs or buts about it. No one really knows for certain. Not any more."

"What a goddamn short-sighted stupid thing to so. I never saw the world before the war but by god the bombs are the biggest waste in all of history. Who even invented nukes?"

"The good ol' US of A. And then bombed themselves into oblivion. Smart of them, hey?"

Sigh. "Well, once you have some tech you surely won't decide to go back to not having it. Especially once the reds have their own nukes. And they lasted, what, at least a hundred years with 'em?"

"Things were good, for a while. I don't remember much, it's been too long, but I remember not being frightened of the bombs. Knowing they weren't actually going to be used. That they were...deterrents. But once you've built a big, powerful weapon, you want to see what it does, after all."

She narrows the list down to the Vaults in the area, marking off the ones James had checked and the ones Amy had plundered. That left her with plenty to go through, but she'd do that back in Rivet City with James. She doesn't want to be down here anymore.

"All right, I've got my list, you've got a new toy to play with, I'm calling this a success. Heading back to you now."

"Right. Right... Stay sharp. It's not a success until we're in the sky."

"True that." 

Amy leads the bots and Edward back to the elevator, and then back up the way they came without incident. She does pause on the showroom floor for the bots, if they would like to loot through the tech on display.

Looting ensues. The bots find a few nuclear batteries in some of the display pieces!

They stay alert on the way back to the roof.