His first task while underwater was to find some breathable air, whether it be air pockets, an exit, or anything else. He couldn't very well explore the place if he was dead... Fortunately whoever built the vault had made some interesting design decisions, allowing a relatively large amount of air pockets to be around the place.

Though, something worried Afton. This was the floor that held the reactors, if they were still active, wouldn't he be electrocuted if he got near them? Of course with most of the vaults lights not working they might be turned off, but the terminals were still active which meant that had a power source coming from somewhere. ​​

He'd seen a couple reactors on the floors above, so hopefully it was just them running and none down here.

Aside from that, the floor was relatively uninteresting. There were a few boxes of ammo that were interesting. He'd collect them once he found the ventilation component, aside from that most of the place looked abandoned.

Eventually he entered a room containing a reactor in it, he almost shit bricks when he saw it, but relaxed when he realised he hadn't instantly died. Scouring the room, he found a locker that contained many engineering components, as well as the differential pressure controller. It was a miracle that he'd found this component specifically, as it was the only one he needed to find that wouldn't be damaged by water.

[Quest updated! : Find parts to repair Bunkers ventilation systems. 1/3]

Grabbing it he quickly made his way back to the duo who were waiting for him. They jumped back as he popped outta the water, handing them the component and checking over his radiation levels on his Pipboy.

He hadn't been in there long enough to get radiation sickness, so it'd be better to leave using the Radaway for another time. It made you rather sickly after using it, so it was best to do it in a safe location.

"Hold up before you say anything." he says, jumping back into the water and dragging the boxes of ammo he'd found to the surface.

"You sure don't do things by half, do you kid?" Karl states as he pulls Afton out of the water.

Afton shrugs, "Caps are caps, no reason to not loot something just lying there." he says, wiping himself off with a rag before putting his gear back on. The wet underwear would be annoying, but he'd live.

"Got what you needed?" Boone asks from the side with his arms crossed.

Nodding, Afton points at the component, "That thing's rare as fuck. Only vaults contain them and similar components... Hope you guys don't mind accompanying me while I search for 'em."

Karl shrugs, "As long as we remember our other objectives, I don't mind."

With that Afton's mission for entering the vault was complete. There was still one last thing they needed to do while they were there though.

A couple hours later the group approach the Overseer's office, Afton had hacked into another terminal which apparently purported to contain the password to the Overseer's terminal. It was unlikely to work, but it was best to check and be sure.

As Afton sat down and entered the password, they were all pleasantly surprised to find that he had indeed managed to unlock it. Though, their faces that were reflected by the terminal's screen hardened when they saw the entries.

[Open sacrificial chamber?]

...

"The terminal's fucking empty... The only thing on here is this." Afton mutters, feeling slightly cheated at the lack of information.

"Youknow, usually I'd be the last guy to say we should head into a literal sacrificial chamber... But that's exactly what I'm sayin'... Something about this just feels, off. Maybe whatever we're looking for is hidden there." Karl says from behind him.

Boone just shakes his head, "We'll probably die if we go in there..." he states simply, not adding his own opinion on whether or not they should head inside.

Afton shrugs, "We'll check it out, if it looks 'fucky' then we'll leave. I'm not going to sit in a suicide chamber without some reassurance." he says before selecting the option to open the chamber.

The floor beneath them creaks as the desk and terminal itself is raised off of the ground. Revealing a hidden entrance that leads into a hallway beneath them.

...

Afton looks at the other two, "Don't step inside just yet. Those Vault Tech idiots forgot to hide the internals of this elaborate hidden entrance. Gonna makesure it doesn't close behind us like some sort of cliche horror movie."

He pulls out his tools and quickly starts fucking with the mechanical components. Jamming scrap metal in between gears, locking pneumatic pistons in place, and severing electric wiring made it so this entrance would only shut if you detonated an explosion on top of it.

Afton sends a thumbs up at the others before stepping inside the brightly lit hallway. Boone gives Karl a glance, the man shrugging nad following his partner inside.

The sniper just sighs to himself, "Well Carla, might be seeing you soon enough." he mutters as he follows them.

At the end of the hallway is a door that slides up as they approach, revealing a large room with nothing but a dirty-looking red chair, and a projector pointing at the wall in front of it.

Again, Afton isn't trusting this place at all, and immediately gets to work at sabotaging the door to allow them to leave should poison gas start filling it or something similar.

It isn't difficult, the door isn't made from the same reinforced steel that the walls are, a few minutes of denting it with his hammer finally allows him to see a few small wires that'd been concealed. He severs one at random which causes the door to immediately shut itself.

It was fortunate Afton hadn't been standing under it otherwise he might've been crushed... At least the wiring was still visible, even with the door shut. Some more fiddling around eventually disconnected the door from whatever was powering it.

Of course, this also forced the trio to manually open and prop it up by jamming a metal bar between it and the floor. Preventing it from closing.