Tau has thought about going to the surface. One of these days, he tells himself, he’s going to plot a course to level 1. If he survives, he’ll go into space. One of these days.
The 15th level is lit up with the occasional streetlight, illumination from within many residences, and the occasional bonfire. The ventilation systems are still functional, so people don’t worry too much about burning things when they have to.
The software that runs most of the urban sectors has been isolated since the war, and nothing’s been updated. The habitat software was wiped out in the attack. Resourceful programmers managed to salvage some of the backups, and reinstalled what they could after the firewalls went up. Tau knows one of them, a woman called Sky. She taught him some useful chants and protocols, but she’s too busy in her own sector to take care of war orphans.
Tau asked Sky about the software once. The firewalls still allow a limited amount of information to trickle down to the 15th layer, but Sky told Tau that it didn’t matter. All the software keys had been revoked and nobody felt safe enough ascending to the higher layers to retrieve new keys - nor did anyone really know whether to trust them or not. Tau didn’t understand it all, but he trusted Sky.
Today Tau made a new discovery. He came across a used warbler grenade. It must have been used during the rioting, since it’s not much good against robots. He found some documentation in the command center where he lives, and found out that the warbler emits sound waves across several frequencies. The old lore of the surviving computers tells him that it makes a noise at frequencies dogs can hear but people can’t. Tau thinks that if he can wire the warbler into the power grid, and maybe get it to just emit ultrasound, he can keep the dog packs away from his refuge. Now that he knows what to look for, he’s going to try and find more tomorrow. And if he can’t, he can try to replace the power cell and just carry it with him.