Therefore, to reach other suns in a reasonable portion of your life expectancy: Accelerate continuously, right up to the interstellar midpoint, at which point you activate the decelerator system in the Bussard module and start slowing down again. You are limited by the speed of light, which you can never quite reach. But you are not limited in how close you can approach that speed. And thus you have no limit on your inverse tau factor.

Throughout her year at one gravity, the differences between Leonora Christine and the slow-moving stars had accumulated imperceptibly. Now the curve entered upon the steep part of its climb. Now, more and more, her folk measured the distance to their goal as shrinking, not simply because they traveled, but because, for them, the geometry of space was changing. More and more, they perceived natural processes in the outside universe as speeding up.

It was not yet spectacular. Indeed, the minimum tau in her flight plan, at midpoint, was to be somewhat above 0.015. But an instant came when a minute aboard her corresponded to sixty-one seconds in the rest of the galaxy. A while later, it corresponded to sixty-two. Then sixty-three… sixty-four… the ship time between such counts grew gradually but steadily less… sixty-five… sixty-six… sixty-seven…

* * *

The first Christmas— Chanukah, New Year’s, solstice festival season— that the crew spent together had come early in their voyage and was a feverish carnival. The second was quieter. People were settling down to their work and their fellows. Nevertheless, improvised ornaments glittered on all decks. The hobby rooms resounded, the scissors and needles clicked, the galley grew fragrant with spice, as everybody tried to make small gifts for everybody else. The hydroponics division found it could spare enough green vines and branches for an imitation tree in the gymnasium. From the enormous microtape library came films of snow and sleighs, recordings of carols. The thespian contingent rehearsed a pageant. Chef Carducci planned banquets. Commons and cabins rollicked with parties. By tacit agreement, no one mentioned that each second which passed laid Earth three hundred thousand kilometers farther behind.

Reymont made his way through a bustling recreation level. Some groups were stringing up the most newly made decorations. Nothing could be wasted, but aluminum-foil chains, blown-glass globes, wreaths twisted from bolts of cloth, were reclaimable. Others played games, chattered, offered drinks around, flirted, got boisterous. Through the chatter and laughter and shuffling, hum and crackle and rustle, music floated out of a loudspeaker:

Adeste, fideles,

Laeti, triumphantes,

Venite, venite, in Bethlehem.

Iwamoto Tetsuo, Hussein Sadek, Yeshu ben-Zvi, Mohandas Chidambaran, Phra Takh, or Kato M’Botu seemed to belong with it as much as Olga Sobieski or Johann Freiwald.

The machinist bellowed at Reymont: “Guten Tag, mein lieber Schutzmann! Come share my bottle!” He waved it in the air. His free arm was around Margarita Jimenes. Suspended above them was a slip of paper on which had been printed MISTLETOE.

Reymont halted. He got along well with Freiwald. “Thank you, no,” he said. “Have you seen Boris Fedoroff? I expected him to come here when he got off work.”