They shut the generator down and inside it hits eight below

Previously: the club dismissed Sabino using the number of the report in which he flagged the flue. Lena's bunk reads 140 ppm.

The ninth day dawned with diesel for four days by the ration's arithmetic and for six by the tank's, and the gap between those two numbers is what decided the morning. Outside it was fourteen below. Inside, in the dining room, two above zero and the wood stove lit since six.

Mercedes Arriaga, fifty-five, retired justice of the peace, who has kept the fuel accounts on the inside back cover of the signature book since the third day, laid the two sums one under the other before anyone had breakfast.

—The ration says four days, because at sixteen litres a day the hundred and twenty-eight of the fifth day run out on the twelfth. But the ration has not been spent. Since Idoia stopped the engine on the sixth day at half past seven we have not burned a single full day: half an hour that day, forty minutes on the seventh so Fani could measure, and an hour and a half last night to eat something hot. There are ninety-nine litres in the tank. Exactly. —She lifted the pencil.— Ninety-nine. The first round number in nine days.

—Six days of ration for four days of waiting —said Idoia Bergara, thirty-nine, warden of the refuge and an emergency nurse until 2019.

—Six and change. Thirty-five litres to spare.

Idoia held on to that all morning, because thirty-five litres to spare is what lets you choose, and she had gone nine days without being able to choose anything.

The first thing, though, was to try to fix it. Sabino Amantegui, sixty-six, warden of that same refuge from 1991 to 2022, had asked three times since Fani Quiroga, geologist, brought down the number from the bunk, and that morning he asked in writing, with Mercedes's pencil, on a sheet of the old duplicate book.

—I'll go up. I have a roll of thin aluminium sheet and two pipe clamps in my rucksack, and tinsmith's shears. It's what I was carrying on Tuesday.

—You came up on Tuesday and you have spent six days in a bunk coming out of hypothermia —said Lena Bouzas, forty-one, mountaineer and anaesthetist, who since the measurement sleeps on the east-side bench and not in the small dormitory.— You are not going on the roof.

Txomin Elordi, sixty-two, shepherd, who has carried the club's mail up to Iratxeta since 1994, settled the part he knew.

—The pitch holds one person. One. And today it is harder than on the sixth day, which is worse: the crust gives no warning.

Idoia went up, as before, roped to the beam of the upper dormitory with the eight-millimetre line. Sabino stayed below the hatch, sitting on the floor with the survival blanket over his knees, calling out instructions; Ramiro Bouzas, forty-four, mountaineer and boatwright, held the rope from the beam and passed her the pieces one at a time through the gap.

What Idoia found up there was what she had seen on the sixth day and now had to handle with gloves at fourteen below. The flue crosses the slab with no sleeve and is broken at exactly that point, on the underside, hidden beneath the overlap of the tile: a clean half circumference, the edges turned outwards and the metal crushed flat on top, where the stone presses it. And the channel tile, the one that covers the overlap, has been broken at the corner since before any of this: the 2021 report Mercedes had read aloud the previous morning described that corner in two lines.

Idoia cleared the snow, pulled out the broken piece of tile, and with that she gained a hand's width of room.

She cut the plate with the shears to the measurement Sabino called up from below, rolled it around the pipe and tightened the two clamps with the spanner. The lower half came out lined and snug. The upper half did not. Up there the pipe is not round: it is flattened against the slab, and a straight plate over a flattened pipe rests on two points and leaves air everywhere else. She had nothing to fill that air with either. There is no refractory sealant at Iratxeta: the cartridge was inside the hundred and sixty euro estimate the club did not approve in 2021.

She came down at ten past eleven with her hands purple and said it plainly in front of the nine of them:

—It is closed underneath and open on top. I do not know how much I have shut. Either we measure it or it is worth nothing.

Measuring cost engine time, and the engine was the thing under discussion. Mercedes wrote it down before anybody asked.

—Forty minutes, like the seventh day: three and a third litres. I take them out of tonight's dinner.

The protocol was the seventh day's, the one they already knew: the data logger belonging to Fani Quiroga, twenty-eight, geologist, who came up to change the sensors on the slope, twenty minutes on the long table in the dining room and twenty hung from the rail of the upper bunk in the small dormitory, a hand's breadth from where Lena had slept for six nights; the nine of them sitting still in the kitchen, which at Iratxeta is the same room as the dining room with a half-height partition; Aitor Sein, seventeen, trainee warden that season, calling the minutes; Mercedes writing down the start time and the stop time.

The engine started at two minutes past twelve and stopped at twelve forty-two. Fani brought the logger down, plugged it into the laptop and turned the screen so that everyone could see it.

—Dining room, forty-one —she said.— It flattens out at seventeen minutes, so that number belongs to the room now. We came from sixty-eight.

—Down four in every ten —said Ramiro.

—Wait. —Fani moved to the other curve.— Small dormitory, a hundred and twenty-one at twenty minutes, and at twenty minutes it was still rising. We came from a hundred and forty.

Nobody spoke for a long while. Casimiro Lete, seventy-one, club member, thirty winters coming up to Iratxeta, did the subtraction from the corner bench with his cap on indoors.

—Nineteen. You have taken nineteen off it.

—The patch has closed the half you can reach from outside —said Fani.— The smoke has gone out entirely through the upper seam, which is the one crushed against the slab and the one that feeds the cavity over the dormitory. I have covered the good door and left the bad one.

Lena stood up and translated the number, which is what she has been doing since the sixth day.

—The eight-hour limit in a workplace is twenty parts per million and the fifteen-minute peak is a hundred. A hundred and twenty-one is over the peak. Sleeping there four nights is doing the same thing as the six nights before, only a little more slowly.

Ramiro Bouzas took a step up to the long table.

—Then we shut it down and we go down. Today. I'll go.

—We look at the couloir tomorrow and I look at it first —said Txomin, without raising his voice.— Not today.

Idoia cut the argument off with the thirty-five spare litres in her head, which was the only new thing she had that day. She put the two options on the table with Mercedes's figures and Fani's, and said them in full so that nobody would have to ask afterwards.

Carry on with the ration: sixteen litres a day, three hours and twelve minutes of engine, water pumped, batteries charged, lukewarm radiators in the two bunk rooms and a hundred and twenty-one parts per million beside the beds for four more nights.

Shut it down completely: zero carbon monoxide from the generator from that moment on. And, in exchange, zero pump —water is made by melting snow in the big pot on the stove, three or four hours a pot—, zero radiators and zero charger: the radio is left with the two batteries there are, one in and one spare, until day twelve.

—And how cold? —asked Aitor.

Fani looked up the temperature channel on the laptop, which the logger had been recording since Fani switched it on on the sixth day, without anyone asking it to, and measured the slope of the two occasions the refuge had been left without an engine: the afternoon of the sixth day and the eighth up to the hour and a half of dinner.

—With fourteen below outside and no radiators, the small dormitory and the corridor go to eight below by the third night. The dining room does not, because it has the stove: six or seven above zero if we keep feeding it wood. The house shrinks to one room.

—Then the nine of us sleep in this room —said Idoia.— On the east side, away from the west partition. Sacks against the corridor doors and the generator room door. And Fani's instrument stays here, on the table, switched on, because the stove burns too and its flue comes out on the other pitch: I want to see it on a screen and not in somebody's headache.

At ten past one she locked the generator room. Sabino Amantegui got up from the bench, crossed the dining room and laid his own key on the long table, the one from 2013, the one nobody asked him for when they dismissed him.

Idoia put both keys in her apron pocket and wrote it down in the signature book, the club's compulsory register, in large letters and in front of the nine of them: "13:10. Generator stopped until day twelve. Two keys, both of them here. 95.7 litres left and they are not going to be burned. Four nights, the nine of us in the dining room. Radio: two batteries".