Page:Stirring Science Stories, March 1942.djvu/24

 bring the ship back in an Earth-bound orbit, another gravitational recorder started functioning. A body about ten thousand miles away, à small body. Presumably another wandering asteroid. They should be frequent here even though this was inside the orbit of Mars. Many asteroids crossed that orbit even though the majority stayed between Mars and Jupiter.

Casually Sedgwick computed the orbit of the new body, saw that it would pass well beyond him and paid it no further attention. It was not until after rockets were accelerating the sphere back towards the Earth that he noticed that his original calculation on the new aster-bidal body was in error. Apparently the mass would pass uncommonly close to where the sphere was. Perturbed over the original mistake, which should have been impossible, he speeded up the rocket a bit and shifted the globe slightly. It should be sufficient to put distance between the asteroid and the ball.

Later he noticed that mistake had again occurred. The asteroid was still heading for an intersection with his sphere. Either the tiny planet had changed its orbit, which was impossible, or somehow the wires and mechanisms of the outside sensitives were deranged. That was possible and it was also dreadfully serious. A meteor perhaps? It might have buried itself into something and created a short circuit somewhere. The dials showed no such thing though and it was unlikely that any single meteor could have fooled all the dials.

Again he shifted the sphere's course and this time he watched the dials registering the asteroid. Sure enough the gravitational sensitives altered slowly and surely to bring the foreign body's shift into a new orbit that would keep it on an intersection with the sphere.

Then Sedgwick noticed something else. That the speed of the asteroid had altered, had accelerated. If the fixed velocity of the little astral wanderer had been the same, it would not have mattered much where it headed. The velocity of the globe was so much greater and was quite capable of outrunning any natural body. But the speed of this strange body had altered; it had speeded up and it had not lost anything of the original distance between them. In fact the man now realized that it was accelerating even more than his sphere and was steadily closing the gap!

This was no asteroid. He was sure of that now. Coldly sure of it and he wondered at himself for his own coolness. Then with a start he recognized his own emotion. It was that calmness that settled over him with every stress and emergency. This then was a serious crisis.

What was this body? He dared not think and yet he knew he must. There was one conclusion and one only. No comet, no asteroid, no meteor could change its orbit. No lifeless body could speed itself up and so diabolically and consistently keep its path in space so that it would overhaul and meet up with the sphere no matter what shift the latter made. This was, this could only be, an artificially created mass, an intelligently directed body, another space-travelling vehicle for an intelligent race!

But from where? From Earth never. From Mars then? Maybe. It was a likely possibility. He had approached Mars. He had hung for a while in space surveying it. Could it be that Mars was protected? That Mars was patrolled? That something was coming to investigate him?

Sedgwick had no mind to allow that. He knew several things. One, that he had no means of communicating with another space-sphere. Two, that his first duty was to bring back his sphere safe and intact with all its records unimpaired. Three, that if alien hands or alien machines tried to pry into his craft, it would almost certainly accomplish ruin and his death.

Therefore Sedgwick ran. Rapidly he activated rockets as fast as the increasing velocity