ZERO SUM

Forty feet down, in the dark, inside a hull that came apart nine minutes ago, Dex Mahurin's rebreather stops.

He knows the exact second it happens because the sound of his own breathing stops with it. Forty feet of black water in the Houston ship channel and the only noise left in the world is the barge groaning as it settles further onto the wreck above him, and the small mechanical click of a man pulling a bailout bottle that is not there, because he clipped it to the guideline at the entry point, because he was going to be inside for ninety seconds.

He has been inside for four minutes.

He is thirty-one years old. He places charges in flooded structures for a living because it pays eleven hundred dollars a day and because he was good at it before he understood that being good at it was a personality. There is a girl he has not called in three weeks. There is a truck with a bad transmission. These are the last two facts his brain offers him before it gets down to business.

The business is a steel plate.

It came down across the compartment door when the hull shifted, and it weighs — he has an eye for this — somewhere between eight hundred and nine hundred pounds, and it is not going to move, and Dex Mahurin puts both hands on it anyway because a man drowns however he chooses to drown.

He pushes.

• • •

In Lagos, at that moment, it is eleven at night and Adaora Ojo is four hundred feet above Victoria Island, where she has been most nights for twenty-two years.

She flies the way other people walk to clear their heads. She has done it since she was nine. There has never been a single day of her life in which she has had to think about it, any more than a person thinks about standing up.

She simply stops.

There is no warning and there is no sensation of loss. What there is, is the absolute and immediate arrival of gravity — four hundred feet of it, with a woman in the middle — and Adaora Ojo, who has never fallen, falls.

She catches it at seven feet.

She will never be able to explain how. She will spend the rest of her life describing it as reaching for a rung that had been taken away and finding, at the very bottom, a splinter of it — and she hits the roof of a parking structure on Ozumba Mbadiwe Avenue hard enough to break her left arm in two places and lies there on the hot concrete staring at the sky and understanding, with total clarity, one thing:

Somebody just took most of it.

• • •

In Seoul it is one in the afternoon and Ha Jun-seo, who is the strongest man who has ever lived, is holding up the corner of a collapsed pedestrian overpass with eleven people underneath it and a fire crew working.

He has been holding it for four minutes. He could hold it for four days.

His knees go.

Not all the way — he catches it, and screams, and the fire chief screams, and twelve people are dragged clear in the next ninety seconds while a man who has never in his life had to try holds four hundred tonnes with everything he has and finds, for the first time since he was fourteen, that everything he has is a quantity with an end to it.

• • •

In a farmhouse in County Clare, an eighty-two-year-old man named Auden Crale is asleep.

He wakes the way he has woken eleven times in sixty years: instantly, completely, and doing arithmetic.

He lies in the dark for a moment with his hand flat on his chest.

Then he says, out loud, to an empty room:

"Oh, my God."

He gets up. He does not turn on the light. He goes downstairs to a desk with a rotary telephone on it and a ledger — an actual ledger, cloth-bound, the eleventh of its kind — and he opens it to a page ruled into columns and he reads the total at the bottom, and then he sits very still for perhaps forty seconds, which is the longest Auden Crale has permitted himself to be still since 1979.

"Fourteen," he says. "Eleven percent."

He is eighty-two, and there are three ledgers on that desk, and the newest one has a hundred and nine blank pages in it, and he had allowed himself lately to imagine that he might die before it was filled.

There is a photograph on the wall above the desk: a school photograph from a primary school in Cork, 1974, with a boy in the second row who has a circle drawn round his head in pencil. Auden Crale has looked at it every morning for fifty-one years and has never once explained it to anybody.

He picks up the telephone.

There are nine hundred and eleven people on Earth with what the ledger calls allocation, and within six minutes, four hundred of them will have received a call, and every one of those calls will consist of the same six words, which have been the same six words since 1963 and which have never once been used:

"Protocol four. It's a large one."

• • •

Under forty feet of water, Dex Mahurin pushes an eleven-hundred-pound steel plate off its seating, out of the doorway, and into the far bulkhead of the compartment hard enough that the impact rings through the hull and is recorded on a seismograph at Rice University as a magnitude 1.1 event.

He does not notice.

He is busy noticing that he has not breathed in six minutes and forty seconds and that this has become, at some point in the last thirty seconds, an entirely academic problem.

He goes out through the door.

He goes up through twenty feet of debris that does not slow him down, and he comes out of the water beside the barge into a sky the colour of a bad bruise, and the crew on the deck of the Marie Colvin see a man they had already begun grieving come up out of the channel like something being born, and the first thing Dex Mahurin does when his head breaks the surface is not gasp.

He looks at his hands.

"Something's wrong," he says.

• • •