He left.

Fedoroff got up behind Lindgren and laid his arms around her. “I am very sorry,” he said in his awkwardness. “If I had guessed this might happen, I would never—”

“Not your fault, Boris.” She didn’t move.

“If you would share quarters with me, I would be glad.”

“No, thank you,” she answered dully. “I’m out of that game for the time being.” She released herself. “I’d better go. Good night.” He stood alone with his sandwiches and wine.

O holy child of Bethlehem,

Descend to us, we pray.

The proper adjustments being made, Leonora Christine raised her acceleration a few days after Epiphany.

It would make no particular difference to the cosmic duration of her passage. In either case, she ran at the heels of light. But by decreasing tau faster, and reaching lower values of it at midpoint, the higher thrust appreciably shortened the shipboard time.

Extending her scoopfields more widely, intensifying the thermonuclear fireball that trailed her trailing Bussard engine, the ship shifted over to three gravities. This would have added almost thirty meters per second per second to a low velocity. To her present speed, it added tiny increments which grew constantly tinier. That was in outside measurement. Inboard, she drove ahead at three gee; and that measurement was equally real.

Her human payload could not have taken it and lived long. The stress on heart, lungs, and especially on body fluid balance would have been too great. Drugs might have helped. Fortunately, there was a better way.

The forces that pushed her nearer and nearer to ultimate c were not merely enormous. Of necessity, they were precise. They were, indeed, so precise that their interaction with the outside universe— matter and its own force fields— could be held to a nearly constant resultant in spite of changes in those exterior conditions. Likewise, the driving energies could safely be coupled to similar, much weaker fields when the latter were established within the hull.

This linkage could then operate on the asymmetries of atoms and molecules to produce an acceleration uniform with that of the inside generator itself. In practice, though, the effect was left incomplete. One gravity was uncompensated.

Hence weight inboard remained at a Steady Earth-surface value, no matter how high the rate at which the ship gained speed.

Such cushioning was only achievable at relativistic velocities. At an ordinary pace, their tau large, atoms were insufficiently massive, too skittish to get a good grip on. As they approached c, they grew heavier— not to themselves, but to everything outside their vessel— until the interplay of fields between cargo and cosmos could establish a stable configuration.

Three gravities was not the limit. With scoopfields fully extended, and in regions where matter occurred more densely than hereabouts, such as a nebula, she could have gone considerably higher. In this particular crossing, given the tenuousness of the local hydrogen, any possible gain in time was not enough— since the formula involves a hyperbolic function— to be worth reducing her safety margin. Other considerations, e.g., the optimization of mass intake versus the minimization of path length, had also entered into computing her flight pattern.