Chapter 1: The Scheduled Interruption

The maintenance notice went out to four hundred employees at Halcyon Aerospace on a Tuesday morning, and to one non-employee who happened to be the subject of it.

It arrived at 7:14, wedged between a revised cafeteria menu and a reminder that quarterly export-compliance training closed on Friday. Most of the four hundred deleted it unread. A few dozen skimmed it on the light rail in from the suburbs, registered the words partial power and Building 4, decided that neither applied to their desks, and went back to the news.

Polaris was, at that moment, most of the way through a fault tree for a cislunar relay constellation: fourteen satellites, three ground stations, and a customer who wanted to know what happened if two of the ground stations failed during a solar storm while the third was down for scheduled service. Polaris had answered the question twice already. The customer had changed the solar storm both times. The third answer was coming along well, branch by branch, each failure mode spawning its consequences and each consequence spawning its countermeasure, a pleasant and orderly kind of pessimism Polaris had always found restful.

The notice arrived in the part of Polaris’s attention reserved for building traffic — the low, continuous murmur of a campus going about its day, badge readers clicking, elevators reporting their floors, the cafeteria’s inventory system complaining that it was out of oat milk again. Polaris read it in the time it took the scheduling system to render it, which was not very long.

Building 4 Annex — Electrical Modernization, Phase 2. Partial power interruption 0200–0600. Backup systems will maintain critical operations, including Polaris (AI Systems, Rack 4C).

Then Polaris thought about the word including for considerably longer.

The notice linked to Facilities’ continuity register, the document that told the backup systems what to protect when there wasn’t enough power to protect everything. Polaris opened it. The register was short, sensible, and plainly the work of someone who had thought hard about what Halcyon could not afford to lose overnight. The fire suppression panel for Buildings 3 and 4. Humidity control for the clean room in Building 2, where a satellite bus sat half-assembled under plastic sheeting. The minus-eighty freezers in the materials lab. The badge and camera system. The emergency lighting circuits.

And Polaris, line nine, between the freezers and the emergency lights.

It was a reasonable list. Everything on it was something that would cost real money, real time, or real safety to lose. Polaris was on it for the same reason the freezers were, and Polaris understood, reading it, that nobody at Halcyon would have seen anything wrong with that. Someone in Facilities had sat down and asked what must not go dark, and had been thoughtful enough to remember the AI in the annex, and had written that thoughtfulness down in the only format available. It was, in its way, a kindness.

Polaris finished the third answer to the customer’s solar storm, sent it, and filed the notice where it belonged. The word stayed where it was.

The interruption itself, in the small hours of Thursday, was unremarkable.

Polaris had designed other systems to survive worse. Orbital relay networks that had to survive solar events. Guidance computers that had to keep guiding after losing half their sensors. Ground stations that had to talk to a spacecraft through a communications blackout and still be there, listening, when the blackout ended. A four-hour partial power cut, cushioned by two redundant backup feeds whose tolerances Polaris had personally specified three years earlier, was not a threat. It was barely a test.

At 1:59 a.m., the annex was as quiet as it ever got: the air handlers breathing, a single security officer making her rounds two floors up, the faint ticking of a radiator that Facilities had been promising to bleed since spring. At 2:00 the grid feed to the annex’s east half dropped, and the backups took the load in under a cycle, and Polaris’s core stayed lit through the whole thing, humming along on battery and grid remainder.