He checked the nearest-object meter. Its reading was what it should be if the Med Ship were aground at headquarters. He checked the hull temperature. Its reading was just what it should be if the ship had been aground for a long time. He checked the screens again. He checked the magnetometer, which gave rather unlikely indications in overdrive, but in normal empty space recorded only the Med Ship's own magnetic field. It now registered a plausible Gauss-strength for a planet like the one on which headquarters was built.
He swore. Absurdly enough, he flipped the switch for the electron telescope. It filled a screen with dazzle, as if there were too much light. He could not use it.
Murgatroyd said impatiently, "Chee! Chee! Chee!"
Calhoun snapped at him. This was completely impossible: It simply could not be! A little while ago, he'd known the sensations of breakout from overdrive. He'd been dizzy, he'd been nauseated, he'd felt the usual horrible sensation of falling in a tightening spiral. That experience was real. There could be no doubt about it.
Instruments could be gimmicked to give false reports. In the course of a Med Ship man's training, he went through training voyages in ships which never left ground, but whose instruments meticulously reacted as they would in a real voyage. In such training exercises, vision screens showed blackness when the mock-up ship was theoretically in overdrive, and star-systems when it theoretically came out. A student Med Ship man went through illusory "voyages" that included even contact with theoretic planets; everything that could happen in a spaceship, including emergencies, was included in such mock-up trips. No training unit could simulate the sensation of going into overdrive or coming out of it, and he'd felt them. This was no mock-up trip.
Growling a little, Calhoun threw the communicator-switch. The speaker gave out the confused murmur of ground level signals, like those a space-type communicator picks up in atmosphere. Through it, vaguely, he could hear the whispering, faintly crackling Jansky radiation which can be received absolutely anywhere. He stared again at the vision screens. Their images were infinitely convincing. Overwhelming evidence insisted that he should go to the air-lock and out of it and hunt up somebody to explain this absurdity. It was inconceivable that a ship should travel for three weeks vastly faster than light and then find itself peacefully aground in its home port. It couldn't happen!
Murgatroyd said impatiently, "Chee!"
Calhoun slowly unbuckled the seat-belt intended to help him meet any possible emergency at breakout, but a seat-belt wouldn't help him decide what was reality. He got cagily to his feet. He moved toward the airlock's inner door. Murgatroyd padded zestfully with him. Calhoun didn't go into the lock. He checked the dials, and from inside the ship he opened the outside lock door. From inside the ship he closed it again. Then he opened the inner lock door.
He heard a hissing that rose to a shout, and stopped.
He swore violently. Every instrument said the ship was aground, in atmosphere, at Interstellar Medical Service Headquarters, but he opened the outer lock door. If there was air there, nothing would happen. If there was no air outside, the air in the lock would escape and leave a vacuum behind it. He'd closed the outer door and opened the inner one. If there was air inside the lock, nothing could happen, but air had rushed into it with a noise like a shout.
So there'd been a vacuum inside the air-lock; so there was emptiness outside. So the Aesclipus Twenty was not back at home. It was not aground. Hence, the appearance of Med Service Headquarters outside was illusion and the sound of ground-level communication signals was deception.
The Med Ship Aesclipus Twenty was lying to the man it had been built to serve. It had tried to lure him into walking out of an air-lock to empty space. It was trying to kill him.
II
Actually, outside the ship there was nothing even faintly corresponding to the look of things from within. The small vessel of space actually floated in nothingness. Its hull glittered with that total reflection coating which was so nearly a non-radiating surface and was therefore so effective in conserving the heat supply of the ship. There was a glaring yellow star before the ship's nose. There were other white-hot stars off to port and starboard. There were blue and pink and greenish flecks of light elsewhere, and all the universe was specked with uncountable suns of every conceivable shade. Askew against the firmament, the Milky Way seemed to meander across a strictly spherical sky. From outside the Med Ship, its nature was self-evident. Everywhere, suns shone steadily, becoming more and more remote until they were no longer resolvable into stars but were only luminosity. That luminosity was many times brighter where the Milky Way shone. It was the Milky Way.
Minutes went by. The Aesclipus Twenty continued to float in emptiness. Then, after a certain interval, the outside airlock door swung open again and remained that way. Then a radiated signal spread again through the vacancy all about. It had begun before, when the outer door was opened, and cut off when it shut. Now it began to fill a vast spherical space with a message. It traveled, of course, no faster than the speed of light, but in one minute its outermost parts were eleven million miles away. In an hour, they would fill a globe two light-hours in diameter—sixty times as big. In four or five hours, it should be detectable on the planets of that nearby yellow star.
Calhoun regarded the light on the ship's control-board which said that a signal was being transmitted. He hadn't sent it. He hadn't ordered it. The ship had sent it off itself, as of itself, it had tried to lure him out to the vacuum beyond the air-lock.
But the ship was not alive. It could not plan anything. It could not want anything. It had been given orders to lie to him, and the lies should have caused his death. But a man would have had to invent the lies. Calhoun could even estimate exactly how the orders had been given—but not by whom—and where they'd been stored until this instant and how they'd been brought into action. He had no idea why.
The Med Ship was inevitably a highly complex assemblage of devices. It was impractical for one man to monitor all of them, so that task was given to another device to carry out. It was the control-central unit, in substance a specialized computer to which innumerable reports were routed, and from which routine orders issued.
Calhoun did not need, for example, to read off the CO2 content in the ship's air, the rate of air-renewal, the ionization constant, the barometric pressure and the humidity and temperature to know that the air of the ship was right. The control-central unit issued orders to keep it right, and informed him when it was, and would order a warning if it went wrong. Then he could check the different instruments and find out what was the trouble. However, the control-central made no decisions. It only observed and gave routine orders. The orders that were routine could be changed.
Somebody had changed them; very probably a new and extra control-central unit had been plugged into the ship and the original one cut off. The extra one had orders that when the ship came out of overdrive it was to present pictures of Med Service Headquarters and report other data to match. It could not question these orders. It was only a machine, and it would carry them out blindly and without evaluation.
So now Calhoun ought to be floating in emptiness, his body an unrecognizable object whose outer surface had exploded and whose inner parts were ice. The ship had carried out its orders. Now, undoubtedly, there was something scheduled to happen next. Calhoun hadn't started the signal. It would not be transmitted—it would not have been planned—unless there would be something listening for it, another ship, almost certainly.