She'll check the dorms before spending any electricity on the power saw, but having it is still comforting.

The dorms looks like something out of a grad student lounge. The hallway leads to a common room with a few bookshelves, scattered plates and dirty clothes, and a few chairs and worn couches facing a a large screen up on the wall. A large bathroom is off one side, and the other opens to a long hallway of doors, each with a nametag. Across the lounge is a stairwell access, and an elevator, it's doors torn half-open like something burst out of it. The sounds of distant structure groaning and dripping water is enough to give Margaret a twinge just hearing it.

The stairwell is too collapsed to get to the stairs, but the damage to the elevator shaft actually makes it more accessible. She looks down the hole, trying to judge whether there's a way out at the bottom and how likely it is that she could climb back up it if there turns out not to be.

It looks like there's at least two levels of elevator doors below, and one above...with the elevator parked at it. It looks like there might be enough hand-holds on the wall to climb down.

She would feel better about this if she had a rope or a cable or something, and spends a while looking through the facility for one, but if she doesn't find anything good she'll go down hand over hand.

A spool of cable turns up in one of the store-rooms. It looks like it might be data cables, but it seems strong enough when tested to take Margaret's weight.

It seems like while Margaret was working, Catherine was watching. "I still haven't had any luck getting into the systems downstairs. If you're going down there, you should bring the omnitool with you."

"Okay. If I find anywhere with the equipment to fix an omnitool it'll presumably have somewhere to set you up." She collects Catherine (with the usual lack of abruptness so she doesn't get startled by the subjective experience jump-cut), finds somewhere near the top of the shaft to anchor the cable on, and starts rappelling down.

It would, Margaret reflects, be convenient if she had ever rappelled in controlled circumstances, but she never did.

The rappelling process comes in jerks. It's not smooth like in movies, as the lack of practice means it's a battle of weight and friction. Also, every time she lets go, she stops hard, like she's even heavier than it seemed like she should be. The levels inside the shaft are labeled. The one at the top of the shaft can't read, with the car hanging in a Damoclean fashion over the shaft, but the one she just came in from was [G: DORM/GATE]. The next level down is [1: LABS], and then there's one more set below. Shining her light down from the small landing inside the doors at the Labs level shows the lower level is [2: MAINT].

It makes a lot of sense that she's lousy at judging her own weight, given that much of it is diving suit and the rest is stuff other than bones and muscles. She gets out at [1:LABS].

The elevator door opens to reveal a set of hallways through the rock, like the one linking the dorms to the research labs and the cargo bay/gate. Halfway down the corridor, it's blocked by a rockfall, covered over with structure gel crust and WAU polyps, but a ventilation duct seems to offer a path onward.

If the diving suit fits, in she goes. She checks, as soon as she's all the way in, that she can move backwards as well as forwards; she definitely won't be able to turn around in there.

It looks like she can get both in and out. Ahead, the duct leads on. After a few turns (and one connection from above) it opens to show she's in a large, octagonal lab , with a lot of work tables and servers cross-wired to each other. The lights are off, and the door out says, "SYSTEM OFFLINE". A large central table has what looks like a cradle for something the size of a refrigerator, but there's nothing on it now but scattered papers and pens. There's plenty of tools, wiring, but there doesn't look to be any spare omnitool parts. There is, however, a computer terminal with an omnitool mounting slot.

She plugs Catherine in anyway and looks for a way to reboot the computer system. Also, will these tools at least let her take the broken omnitool apart and see what's wrong with it?

When Catherine gets plugged in, the lights in the room come on , and the door lock switches to a healthy yellow "SWIPE OMNITOOL" message. "Huh...oh, there's a lot about the ARK in this system," Catherine says. "We made it to the labs?"

"Yes! Is there anything in there that you didn't already know?"

"It looks like there's a test version of the ARK around here, can you fire it up? If I look at the diagnostics, I can figure out better how to make sure we can get into the ARK when we get to Tau," Catherine says. "Also, there's a payload scanner here they used to look for cracks in the casing--if you can get inside of it, we might be able to get a better sense of how you're put together."

"Oh, those both sound really helpful." She starts on booting up the test ARK, now that the computers are responsive.

The test version of the ARK seems a little buggy still, as it's got far more modules loaded into it as options than the system it's hooked to can run at once. The system only has a few petabytes of active storage, and several of the packages are hundreds of terabytes with the option for selecting all at once totaling two or three petabytes. Sorting out the redundancies and dependencies is tedious, but at least it's fairly specific about which modules depends on which other modules.

It's kind of reassuring, in a way, that the full ARK world is that much data. Makes it feel more likely to feel, not real exactly, but not stripped-down, from the inside. Also looking at parts of the code makes it feel more real in the sense that she starts having hope she'll actually get there, which she was trying to avoid because she expected it would hurt. It does hurt.

She starts disabling leaf-node packages, and then disabling the packages that those packages depended on, and so on down the tree until she has just the core packages and a small handful of add-ons that all fits in memory. (A few petabytes of RAM is about 20 doublings over what she remembers for consumer hardware, so Moore's law definitely slowed down or stopped eventually, but it got quite a ways along first and who knows what other tradeoffs this system is making.)

Before the simulation fires up, the test ARK wants her to select a set of options for the occupant. There's the same list of options from the storage banks in the scan room, Margaret herself, David Munshi, a few others, and one marked "DUMMY".

"All right, great," Catherine says. "Load in the dummy scan, and I can see how I did this before. Once it's running, slow down the clock rate, and then pause it and run the diagnostics."

She does as instructed. "What's the dummy," she asks idly, "an interface for a brain scan with no implementation behind it, or not even that?"

"Yeah, it's a completely original composite I made for debugging the ARK before we got the scans fully working, attempting to see how the 3ns scans would interface with the environment wrappers," Catherine says.

"That's definitely better than testing it on yourself."

Eventually the basic-version ARK finishes compiling.

The simulation starts up, and the Margaret is able to pause it and start the diagnostics. "Ohhh," Catherine says. "I see. The implementation makes so much sense that way--such a perfect way to manage the memory resources and the sensory input handling is so precise."