Winter Mass is held in one building. A stave church of tarred black timber on the high plateau, dragon heads on every gable, raised before the megacity had surveyed the ground it stands on. The towers arrived later and stopped at the edge of the graveyard. From the door the skyline fills the whole arch, close enough to count the lit floors. The church does not face it.
Inside, the nave is all candle heat and cold iron. Hundreds of flames in iron racks, chandeliers hung on chain, and behind the altar a wall of server racks wired straight into the old carving, cable running up the columns like ivy. The altar is a slab of red stone under the jaw of a carved dragon, chains laid across it and gone white with frost, a chalice left standing. Snow comes in through a door nobody closes.
Iron North does not let its own die alone. When one of the clan is wounded past repair, they are carried up through the snow to this church and laid before the red stone, and the whole line gathers around them. Nobody bargains with what is coming. They stand, they keep the candles burning, and they stay until the last signal drops off the network. The clan calls it the disconnection. It is the only surrender Iron North has ever witnessed, and it witnesses it on its feet.
The racks behind the altar are what remains. They carry no traffic and answer no query from the grid. They hold the lines: every name, every oath, everyone who was carried in and did not walk out. So the clan returns, as often as it needs to and always in the coldest month, for the Winter Mass. To say the names aloud. To light a candle for each. To honor them, and to celebrate that they were here at all. The Undercroft makes the machine sacred. Here the machine is only the keeper. What is sacred is the memory.
A slow pulse and a heavy low end, dark at the top the way the building is. Candle heat, cold iron, the hum of the racks that keep the names. One hour of vigil for the ones who disconnected, grief carried the way Iron North carries everything, without bending.