Hug. 

Things do not stay that quiet. There's a cold snap and a gang raids the library for books to burn; Lorica attempts to offer to get a heater running wherever they're living instead and they interpret that as a threat and manage to graze her with a bullet before Rete's nearest mobile chassis can shove her down and scare them off. Trying to return a functioning game console to a house gets the Prius blockaded for hours with the salvage chassis in it, although nobody manages to do worse than scratch its paint. The little girl with the blanket fort lets Fëanáro draw her out with candy and singing and then insists - wordlessly; turns out she has her tongue cut out - on sitting on his lap until he's going to sleep and then attempts to gut him with a letter opener and flings herself off the balcony and suffers head trauma and lingers for two days and dies. Rete has raided the hospital and two pharmacies but there's a limit to what it can do with past-date drugs and only the machines Lorica can get running again. (Lorica points out that if the kid didn't have a tongue the thing with the candy was probably part of a ploy to begin with.)

Supplies fall from the sky. They can get food reliably, a reasonable nutritional variety, and water, and, irregularly, other incidentals. The quantity of garbage and unhandled sewage in Walled Baltimore mounts; Rete can consolidate some of it out of their way but it's still limited to chassis made out of sewing machines and dishwashers and someone's Aibo. Nobody is ever convinced to outright trade for their stuff, but it's not hard to steal.

Rete takes things from the Visionary Art Museum - the prettier ones; some of them are deeply amateur and/or trippy instead - until Fëanáro can spend most of his time in a little art maze in a corner of the library, listening to music on the radio.

Once he has a computer he and Rete work up something short and inelegant for Prius armor. He writes it to the glass. It's designed so every time he does it it'll get a little stronger, so he keeps at it even once the windows are almost certainly bulletproof. He keeps at it until he can no longer concentrate for that long. 

He has a hard time falling asleep, and doesn't wake up any less tired; eventually he cannot sleep at all, and asks for the necklace back. He gets restless. He paces. He goes up and down the emergency stairwells for days at a time, stops only when his limbs are all numb. His heart rate climbs and he can't make it stop. He startles easily. He starts experiencing muscle tremors.

He privately swears not to snap at Lorica because he doesn't want to snap at Lorica. He snaps at Rete; it doesn't mind. His resting heart rate hits two hundred beats a minute and keeps climbing. He doesn't control his body anymore but he's still aware of it the way a human never could be. He can feel himself crumble. He wrestles back some concentration. He leans his head against the cool metal of the Prius and reinforces the glass. His resting heart rate hits two thirty.

Rete puts him on beta blockers.

Helps a little. He reinforces the Prius body as well.

Rete finds other things to try. "I can blood type you," it says, after dispensing some pills. "If you're compatible with Lorica you could offload some adrenaline, she can metabolize it normally, you could keep exchanging blood indefinitely."

"'d be a bit surprising, we're different species. But if you want."

It checks.

They are not a compatible species. He starts having panic attacks triggered by gunshots, changes in lighting, sudden sounds, sunny weather, people moving around anywhere in the range he can sense them, and eventually nothing at all.

Does it help if Lorica hugs him or not.

Not especially. But he doesn't snap at her.

He gets delirious. He alternates between crying that he wants to go home and telling Lorica angrily that she's not his mother. Eventually Rete's current scavenged-medication cocktail seems to stabilize him, sort of.

It's not a very stable stable.

Lorica has enough parts that she and Rete can make do without him. They effectively have been for a while.

"If I come back sometime with a body for you try to find it," she says.

"Kill him."

She hugs him.

"Stupid horrible world."