Night Walk

two

There are roughly eighty thousand portals between Emm Luther and Earth. To make the journey home you must pass through all of them, regardless of how afraid you become, regardless of how far you feel body outstripping soul during the flicker-transits across the distant reaches of the Rim.

Your ship reaches the first portal by diagonally breasting the galactic drift for almost five days. The portal is relatively close to Emm Luther at present, but they are separating from each other at a rate of some four miles a second. This is because the planet and its parent sun are swimming with the galactic tide, whereas the portal is an imaginary sphere anchored to a point in the immovable topography of null-space.

If your ship carries good astrogation equipment it may enter the portal at speed; but should the computers in control have any doubt at all about their exact location, they may spend days discarding velocity and maneuvering for position. They know — and you, sweating in your G-cell, know too — that if the ship is not safely inside the portal when the jump takes place its passengers will never again breathe the soft thick air of Earth. The alien geometry of null-space will take care of that.

As you wait, with dry throat and icy forehead, for the relays to strike you pray that some crazy fluke won’t cast you up innumerable hopeless light-years from home. But this is human emotion at work.

Null-space is incomprehensible, but it is not irrational. Provided every glass and metal organ in the guts of your ship is functioning properly, you could make a million jumps from A through null-space to B without the slightest mishap. The difficulties arise because null-space is not reciprocal. Having reached B, the same jump in the opposite direction will not return you to A; in fact, it will take you to any random point in the universe except A. Once that has happened there is nothing for it but to go on making more and more random leaps. If you keep it up long enough and are extremely lucky, you may emerge within reach of a habitable world, but the odds are not good.

In the first century of interstellar exploration Earth alone dispatched some forty million robot probes, of which less than two hundred chanced to make their way back. Of that number, exactly eight had found usable planetary systems. Not one of the handful of manned ships that accidentally made open-ended jumps was ever seen again — on Earth, anyway. Some of them may still be going, carrying the descendants of their original crews, cosmic Flying Dutchmen glimpsed only by uncomprehending stars as their destiny of flicker-transits gradually takes them beyond the reach of human thought.

The eight successful probes of that first century established zigzagging trade lanes, which the manned ships that came afterward were very careful to follow closely. That is the other aspect of null-space travel that troubles you as you wait for the relays to act. Although it was a logical deduction from the absence of reciprocity in null-space, a few pioneers discovered the hard way that jumping from a point near A will not take you to a corresponding point near B. Get more than about two light-seconds from the established jumping-off point, the so-called portal, and you are off on your own random pilgrimage to the far side of eternity.

That is why, during the final slow seconds as you float in your G-cell and breathe the rubber-smelling air, you pray and you sweat.

That is also why the planet Emm Luther, formerly a colony of Earth and now autonomous, jealously guarded the few strings of figures locked in Sam Tallon’s brain. Emm Luther had only a single continent, and her devouring need for new breathing space equaled that of Earth itself. She had one incredible stroke of luck in a probe that found a green planet only four hundred portals out and less than two thousand back.

All she needed was time to consolidate her hold there before the big ships — the invincible sperm of Earth’s ceaseless self-multiplication— — could storm the new and fertile womb.