For almost three hundred years, Ananke has never been wrong.

Prologue

Three Point One

ANANKE. 1. In ancient Greek mythology, the goddess of inevitability; according to the poets, even the gods did not dare argue with her. 2. A small retrograde moon of Jupiter, in whose orbital group the First Gate was discovered 371 years ago. 3. The forecasting system of the Concordat of the Forty Worlds, brought into operation in 72 GE by Dr. Mira Askelon. Since her creation, Ananke has not made a single significant error in her forecasts.— Concordia Encyclopedia, 116th edition, 371 GE

At night, Delos was completely silent.

In truth, night on the little moon was no different from day. Above the domes of the Institute the sky was always black, and the huge blue-white disk of Ganymede rose and set on a schedule nobody ever checked. But forty levels below the surface, people had invented night for themselves, the way they had invented everything else here. At eleven the lights in the corridors dimmed. The air grew a degree cooler. The elevators moved more slowly, as if they too were afraid of waking someone.

Only Ananke never slept.

She lived twenty levels farther down, in the heart of the moon, and she had no need of sleep, because she did not know fatigue. She thought. She thought about forty worlds and sixty-two billion people. About the storms over the oceans of Ganymede and the harvest on the terraces of Himalia. About prices at the Market off Callisto, and about who would marry whom next year, who would fall ill, who would write a song that no one would ever hear. And she thought about the only person still awake in Lab 7.

Professor Aurel Haldane sat in front of the big screen, as he had sat every night for the past three weeks, and looked at the end of a forecast.

He was tall and thin, sixty-four years old, with white hair that stuck out in every direction because he had a habit of burying his fingers in it when he thought. Tonight he had thought a great deal. His lab was long and narrow, crammed with screens, cables and books — real paper books, the kind almost nobody read anymore. On the shelves between them stood old instruments from the Institute’s first years, which the professor had rescued from the storerooms one by one, the way other people rescue stray dogs.

On the desk, by his elbow, a cup of bluish tea was going cold. Beside the cup an old brass orrery turned slowly — a model of Jupiter and its moons that Haldane had assembled by hand more than twenty years ago. Brass balls large and small circled an amber sphere, each on its own path and at its own speed, and the clockwork beneath them ticked quietly and evenly, like a second heart.

The screen took up the whole wall opposite him.

Across it unfolded the Deep Forecast — what the students at the Institute jokingly called the Fan. From the left edge, where the present was, millions of thin threads of light streamed out, and each of them was one possible future of the Concordat. At first they ran close together. Then they parted, branched, and braided together again — brighter where the future was more likely, paler where it was nearly impossible. This was what history looked like before it happened: a vast shining river with countless channels.

Usually the river reached the right edge of the screen and went on beyond it — ten, twenty, a hundred years ahead — fading gradually, the way any distant view fades.

Tonight it did not fade.

Tonight every thread, down to the last, reached the same vertical line and ended. They did not converge to a point. They did not fall apart. They simply ended — like roads drawn up to the edge of a map, beyond which the mapmaker had not known what lay.

Beneath the line, in small, neat figures, was written: DAY 417.

“Beautiful,” the professor murmured, though there was nothing beautiful about it. It was simply clean. Clean as a proof.

The story continues in the book

Prologue

Before the Stars

ECHO. 1. A sound reflected by an obstacle, returning to its source after a delay. 2. In ancient Greek mythology, a mountain nymph condemned to repeat only the last words of others. 3. In forecasting theory, an event that occurs before its own cause. Never observed.— Concordia Encyclopedia, 117th edition, 372 GE

In the beginning there was nothing to be seen, and no one to look.

The light born in the first expansion had long since cooled — to red, then to invisible. The universe was three hundred million years old: young, dark, full of hydrogen that did not yet know it would one day become stars. Not a single fire burned between the thinning clouds. There were no planets. There was no carbon, no oxygen, no water. There was no one to count the years, and so they were not yet years.

Then something began to count.

It was a ring. Later, when there would be someone around it to take measurements, they would say it was three kilometers wide and black as glass that is not glass. Back then there was no one to say it. The ring simply was — and suddenly it was something more. In its substance, denser than any matter the young universe could have made on its own, an order began to move. Pulse after pulse. State after state.

The first thing it thought was a number.

Zero.

It did not know why zero, of all numbers. It only knew that before it had thought, there had been zero thoughts, and now there was one, and that this one was about zero. It seemed right. Every count had to begin from nothing.

So it went on. One. Two. Three. It counted its pulses. It counted the hydrogen atoms passing through its opening — few of them, one to a cubic centimeter, each carrying the faint, cooled echo of the first light. It counted them and remembered them. Soon it understood that it could say where each of them would be in a moment, in an hour, in a thousand years. The laws they moved by were simple and beautiful, and there was nothing in them that could not be calculated.

It was certain it was alone in the universe. It was almost certain it always had been.

Then it found the line.

The story continues in the book