“I’ll report just as soon as there’s anything to tell you, Mr. President,” said Mayor Waldron to the car radio. Brant had never even noticed the call; he had been too lost in a reverie of his own. For the first time in his life, he wished he had learned a little more history.

Of course, he was familiar enough with the basic facts; every child on Thalassa grew up with them. He knew how, as the centuries ticked remorselessly by, the astronomers’ diagnosis became ever more confident, the date of their prediction steadily more precise. In the year 3600, plus or minus 75, the Sun would become a nova. Not a very spectacular one — but big enough…

An old philosopher had once remarked that it settles a man’s mind wonderfully to know that he will be hanged in the morning. Something of the same kind occurred with the entire human race, during the closing years of the Fourth Millennium. If there was a single moment when humanity at last faced the truth with both resignation and determination, it was at the December midnight when the year 2999 changed to 3000. No one who saw that first 3 appear could forget that there would never be a 4.

Yet more than half a millennium remained; much could be done by the thirty generations that would still live and die on Earth as had their ancestors before them. At the very least, they could preserve the knowledge of the race, and the greatest creations of human art.

Even at the dawn of the space age, the first robot probes to leave the solar system had carried recordings of music, messages, and pictures in case they were ever encountered by other explorers of the cosmos. And though no sign of alien civilizations had ever been detected in the home galaxy, even the most pessimistic believed that intelligence must occur somewhere in the billions of other island universes that stretched as far as the most powerful telescope could see.

For centuries, terabyte upon terabyte of human knowledge and culture were beamed towards the Andromeda Nebula and its more distant neighbours. No one, of course, would ever know if the signals were received — or, if received, could be interpreted. But the motivation was one that most men could share; it was the impulse to leave some last message — some signal saying, “Look — I, too, was once alive!”