I get up at five. It is not heroic: the light is at its best before breakfast and the caves are most stable before the sun warms the surface. I drive out to the lagoon in the dark with a thermos and a headlamp, and I walk to the glacier with my axe over my shoulder like a man going to chop wood.
The first thing I do is stand still. A glacier is never silent. If you stand at its edge in February you can hear it tick, a sound like a clock in a different room, and every so often a low groan from somewhere deeper. This is the ice flowing, perhaps a metre a day on this tongue. It is also the only warning you get.
This year the cave we use most opened on the sixth of January, much later than usual, because of a rain at Christmas. It is a short walk from the road, perhaps 400 m across black ash, and the entrance is a low blue mouth in the ice, wide enough for a pickup. Inside, the roof rises to maybe fifteen metres and the walls are the colour you see in a swimming pool at dusk.
On the twelfth I took my first group in. We stood in the middle with the headlamps off and listened to the meltwater running somewhere at the back. Nobody said anything for four minutes, which in a group of eight is a record.
On the nineteenth, the roof had a new crack. It was thin enough to miss, running from the entrance to the left wall, with a small shelf of fresh ice dust on the floor below it. I stood and looked at it for ten minutes. Then I turned the group around.
People expect me to be sad on days like that. I am not. The ice does what it likes, and my job is to be there when it does something else. We spent the day on the Hoffell glacier instead, in a second cave I had been saving for the end of the week, and I think the group liked it more. They told me so at dinner, in the end.
The cave on the lagoon fell on the second of February. Nobody was inside. I walked out to look at it the next morning: a heap of blue blocks the size of cars, and a new mouth in the ice behind it. The glacier makes a new cave every winter. That is the whole point of it.