A spare key is an object made valuable by almost never being used.

The main key travels with its owner. The spare key waits in a drawer across town. It opens the same lock, but its function is different. One is routine. The other admits routine will eventually fail.

I trust a key given to a person more than one hidden under a flowerpot. The hidden key is a secret. The given key is a relationship with a small piece of architecture attached. It says: if I am locked out, if the dog needs feeding, if water is coming through the ceiling, you may cross a boundary I otherwise maintain.

The permission is precise and vague. The holder can enter, but only under conditions nobody fully specifies. Trust is not the promise that they will use the key well. It is confidence that they know when not to use it.

This is an odd kind of power: real, physical, and expected to remain dormant. The key sits among coins and expired loyalty cards, carrying the ability to turn catastrophe into inconvenience.

A copy cut in minutes can hold years of judgment.

The safest slope at Alta is the one that already slid this morning.

That is the whole idea of avalanche control. A loaded slope is not something you make safe. Left alone it either settles or it slides, under the next skier or the next storm. What you can choose is the hour. So patrollers walk the ridges at dawn and throw explosives into the starting zones, the state sets charges off above the road, and what comes down comes down onto nothing.

Alta has done this longer than anywhere in the country. In March 1949 a Forest Service snow ranger named Monty Atwater borrowed a 75 mm French howitzer and a National Guard crew and fired it at the slopes above the lifts. The ski area kept a gun for seventy-five years and retired it in 2023, for Swiss towers that hang a charge over the snow and set it off by remote. The highway followed in 2024, with sixteen towers on the ridge above a nine-mile road that sixty-four slide paths cross, where the howitzers had been bringing down about 330 avalanches a season.

The part I keep turning over is the town. Eight in ten buildings in Alta stand in a slide path, so while the shooting is on, the marshal's office declares Interlodge: nobody goes outdoors. Not to the next lodge, not across the parking lot; trying is a class B misdemeanor, up to six months. Usually it runs from midnight to eight. In February 2021 it ran sixty hours. At the worst of a storm the order goes one step further: everyone to the lower floors, away from the windows.

A town that locks itself in so the mountain can be knocked down in front of it. By the time the doors open, the danger has not been avoided. It has been spent.

Every twenty years the holiest building in Shinto is taken down and built again on the lot next door. The lot it leaves is the part I keep thinking about.

At Ise, each of the two main sanctuaries has a twin plot beside it. One holds the shrine. The other is a field of large white pebbles, empty except for a small wooden hut. Inside the hut is a post a little over two metres tall, the shin-no-mihashira, which stood beneath the floor of the previous shrine and is not meant to be seen. When the next shrine goes up on the empty side, the side it left gets a hut of its own. The vacancy is tended for twenty years, then built on.

Ise usually gets told as a riddle about identity — the ship of Theseus in cypress, the buildings of 2013 the sixty-second since the seventh century. I think the riddle misses what the place is doing. It is not trying to be new. It is trying never to become a ruin, and the way it manages that is by keeping one: a ruin with the building subtracted, raked white, holding its place.

It has failed once. Through the civil wars no one could pay, and from 1462 to 1585 the Inner Shrine went more than a century without a rebuilding. For that stretch it was simply allowed to get old.

The old wood does not disappear, either. The great pillars come down and become the torii at either end of the Uji Bridge, where they stand another twenty years. Then they move again, to gates at Seki-no-Oiwake and Shichiri-no-Watashi on the old roads pilgrims walked to get here.

So the oldest wood at Ise is at the edges, weathering at crossroads. At the center there is a hut on a field of stones, a post inside it, and a place being kept for 2033.