As it turned out, Nike Quinto had been counting on a few more surprises than most of the other men. When he received Eric Furchtbar’s short message he remained completely calm. Ron Landry stood next to him and tried to see over his shoulder. Nike turned and gave it to him reproachfully.

"No need to kibitz, Major, when you can read it for yourself."

Ron took the plastic strip and read it. He swallowed once, read it again, and then found his voice. "They’ve really been shaken up over there," he said. "Looks to me like they’re having hallucinations."

Quinto glared at him angrily. "Any, more amateur remarks like that and my blood pressure will hit the top!" he upbraided him. But his voice didn’t have its usual force.

Ron was amazed to see that Quinto was taking the message seriously.

"Haven’t you ever seen an invisible person before?" continued Nike—then corrected himself. "I mean, one who can make himself invisible? All he’d need for that would be an Arkonide transport suit."

"I wasn’t referring to that, sir," argued Ron. "The fact that the intruders are invisible doesn’t bother me at all. It’s how they got on board that bugs me—when the BOB 21 has a strong defence screen."

Quinto dismissed the objection with a wave of his hand. "At the time when the two vessels grazed each other there must have been a second or so when the screen was weakened—its energies taken up by having to absorb the impact. We only have to imagine that the aliens foresaw that moment. They made themselves ready for the transfer, and at the right instant they simply jumped."

Ron had an impression that Quinto was overrating the strangers’ intelligence but he kept his thoughts to himself. As silently as the others he sat there and waited for further news from the BOB 21.

About an hour went by without untoward event. At brief intervals Furchtbar reported his various efforts to make contact with the unseen intruders. Either they weren’t able to understand his attempts to approach them or they were avoiding any contact. Eric was apparently getting desperate. To all appearances the aliens were keeping quiet but they were getting an unbearable psychological pressure on board the station. Nike Quinto soon found himself in the role of "chaplain" where he had to reassure and console the other commanders. Surprisingly, he was fairly good at it.

At any rate, he didn’t have to exert himself for very long.

Between 17:00 and 18:00 hours the aliens began to stir. Then suddenly things began to happen so fast that the men on board the Joann had trouble making rhyme or reason out of the rapid succession of incoming reports.

*

Art Cavanaugh had a lively imagination yet kept an open mind. He took a great interest in the new situation on board the BOB 21 but without the feeling of panic that seemed to be gripping the majority of the crew members as the hours passed.

Before he was promoted to sergeant, Art had taken many courses and attended many special seminars, all of which was required of any sergeant in the Terran spacefleet. Nobody could rise to one of the highest non-com levels without having a broad education in the various branches of modern science and technology. So Art Cavanaugh was not in danger of being led into wild conjectures concerning the strange invisible visitors. He knew how to differentiate between fantasy and plausibility. He did not believe for one moment that here at last was a manifestation of all the old ghosts of myth and legend which had been reported on Earth for thousands of years—an attitude which had since taken hold of the crew.

With Art is was different. He decided there were just two possibilities. The aliens might have a method of adjusting the index of refraction of their bodily substance to the surrounding air in the ship. This was the more classic method. Or they were producing around them one of those R^-9 fields which were capable of bending light rays. R^-9 designated the distance from the skin (if they had any skin) in which the field would remain effective. It surrounded the object to be made invisible in a thickness of only about 100000th cm. this was necessary because the light rays going around an obstacle had to travel farther than a straight-line ray. If the field were too "fat" around the invisible person, then even the most unbiased observer would notice certain curious distortions of the background behind the interloper.

Of course even a good R^-9 field produced some distortions but one had to realise that the invisible ones would be careful to take this into consideration. Art kept a sharp lookout but no matter how much he stained his eyes he couldn’t detect the slightest distortion effect anywhere.

He admitted that the aliens could also have an entirely new system of some kind. In which case he was sitting here racking his brains for nothing. Maybe it would be better to think out a way of making contact with them. He wondered what would happen, for example, if he were to reproduce on a piece of paper the scope patterns of one of their transmissions—showing the modulations that none of the Terran techs had been able to decipher. For them the pattern would be familiar and they would be alerted to the fact that somebody was trying to get through to them.

Art was fascinated by this idea. He got busy with the auto-recorder machine and wound back one of the used tapes to where a portion of the hours long transmission was available which they had started to pick up after the first of the bombs had exploded. He coupled this part to the oscilloscope and let it play. Then he procured some writing foil and a ball stencil. When the image formed on the green-glowing screen of the scope, he at first studied it for several minutes. When he had finally memorised the modulation pattern, he began to draw. With slow, careful strokes he sketched in the sinusoidal outlines of the carrier wave and added the dips and peaks of the envelope that carried the information. But he began to have his doubts in the middle of his work. He tried to place himself in the aliens’ situation. If someone presented him with a Terran radio message, especially if in code, would he know what it was supposed to communicate? Not for certain, he had to admit.

He stopped his work and pondered over it. There was a dead silence in the Com Room. At least to Art’s ears it was silent because the soft humming of the equipment was something he had long ceased to be conscious of. While lost in thought his gaze wandered along the rows of switching panels, indicators and decoder equipment to his right. During this he noted that one of the main control dials was moving.

Startled, he looked at it closely, suddenly keenly alert. The dial was still turning slowly but methodically. It was the power control for the main transmitter and somebody was turning it to maximum.

Art jumped up, realising that the present equipment setup wouldn’t take, the full-power load. Just now the main transmitter wasn’t connected. They had been using a smaller auxiliary line for communications with the Joann. If the invisible idiot really needed so much transmission power to beam out his message, why didn’t he put in the main transmitter first?

He made an angry leap and attempted to stop the motion. If one of the phantoms were close by he must have drawn to one side because he didn’t feel any contact with anyone. He gripped the dial firmly and tried to turn it back. He was prepared to desist at the first sensation of pain because he knew what Eric had experienced. But the expected resistance wasn’t there. He turned the dial back to its previous setting so as not to overload the other equipment. Releasing it he heaved a sigh of relief but continued to observe.

Apparently the unseen presences had given up their try. The dial remained in its place. No one attempted to turn on more power. Art wondered what they had probably had in mind. Also he wondered what had caused them to give up so quickly. He finally relaxed and was about to take his seat again when everything changed. That was the moment when he learned that the phantom invaders were not about to change their plans because of a little resistance.

Before he reached his chair, something struck him on the head. he fell forward but simultaneously fought against unconsciousness with more strength than anyone would have attributed to him. A dark mist formed in front of his eyes. When he heard the hum of the equipment again the sound seemed to come to him through a long, narrow corridor. He was trying to support himself on his arms but they felt like clay. He could do nothing to prevent them from collapsing under him. He finally lay there on his stomach and it didn’t seem likely that he would ever stand on his feet again.

Breathing deeply, he subdued his vexation and anger as he lay there on the deck and forced himself to relax. Whatever had hit him had paralysed part of his nervous system, and as long as it wasn’t functioning there was nothing he could do. He needed a few moments of rest.

He tried to look around but from his angle of vision he could only see a section of floor. There was really nothing to be seen but the floor since there was no visible trace of the invisible aliens. After some time had passed, Art tried again to support himself on his arms. He knew the strangers would see him move if they were still present but he didn’t care. He had to get on his feet. They were about to destroy the transmitter equipment. He had to inform Eric Furchtbar. After that, they could do what they wanted with him.

His efforts succeeded. He tested out his muscles for a few seconds and knew that he was functional again. Then he suddenly lunged upwards and felt a surge of triumph when he stood solidly on his feet. They hadn’t hit him hard enough—he was still in one piece! He sensed a trace of weakness but knew that would go away if they left him alone for a few minutes.

He could still hear the hum of the equipment but it didn’t sound the way he was used to hearing it. When he turned around he suddenly knew what was wrong. All the equipment was straining under an overload of power. Sharp, blinding lines danced in confusion on the oscilloscope screen. The illuminated indicators on the meters were trembling at their maximum positions and the distribution box Art was standing in front of was radiating dangerous amounts of heat.

He glanced at the power dial and saw that somebody had turned it to its full position while he’d been lying on the deck. All of the output of the generators for the Com Room was being fed into the equipment. It was actually enough power to operate the entire 25 transceiver stations on board the BOB 21 but just now only three of them were turned on. Art could mentally visualise the deck plates bending and melting. He could imagine the meters exploding and the circuits blasting to pieces. He realised that in a few seconds the BOB 21 would cut be off from all contact with the outside if he didn’t take action.

He ventured a second time to reach his seat. He only had to turn on the intercom and inform Eric Furchtbar. Eric would see to it that the invaders were held in check. On his second step, Art halted on his own volition. The intercom mike on the console was showing a wisp of blue smoke. The power overload had burned it out.

The only way left was through the door. Art plunged toward the door, hoping to yell out to the first man he saw what was going on in the Com Room. Whoever might hear him would have to get to Eric and tell him. He himself would have to stay at his post to keep an eye on the invisibles.

He didn’t quite reach the bulkhead hatch. Within 2 meters of it he suddenly had the feeling that somebody was coming at him. He weaved to one side and the blow grazed his shoulders this time driven by much more force than the first one. He only staggered, managing to keep on his feet this time. But he knew that he had to face this menace alone now. They were blocking his way out and the intercom wasn’t working. The fate of the station lay in his own hands.

He took a few seconds to think. Why were they doing this? Why were they overloading all the equipment with full power? Did they simply want to destroy all the instruments? They could do it easier by just smashing the main control panel. If cut off from the outside, the BOB 21 would need half a year to get repaired. So that couldn’t be it. What the devil were they trying to do?

He didn’t find out. He only knew they were in the process of demolishing his equipment—all his shining equipment on which he had lavished more care than his own person during all these months. They just came on board uninvited and without asking. They kept themselves from being seen or identified and acted as if the station were theirs. And now they were starting to destroy Art’s most precious possession—his com equipment.

Art’s anger got the better of him. He threw himself forward toward the power control. He knew this try was going to cost him trouble but he gripped the dial and with a hefty twist brought it around to zero. The loud humming died down swiftly. The lighted indicator needles fell back, and even the intercom mike stopped giving out smoke.

Art looked around him in triumph. "Alright!" he shouted. "Where are you now?"

Something was coming toward him. He could sense it. He couldn't see it but he had a clear impression of approaching menace. He jumped to one side and something struck full force against the top of the distribution box which he had been standing in front of. Art laughed scornfully. Apparently the invisibles were slow to react. He took a step back and again had the feeling that he had only missed a hefty blow by a few millimetres.

He wondered about that. Didn’t they have any weapons other than knives and fists? If that were so then his chances weren’t quite so bad. He had his instinct which seemed to sharpen every time he was attacked. How many invisibles were in this room? Art was certain one of them was standing by the door to prevent him from leaving. Another one must have been occupied with the power control. That made two. Were there any more of them?

For a second time he approached the door. He moved slower than before so that his, instinct would have time to warn him. When he was 2 meters away from the exit he sensed that somebody was standing close in front of him threateningly. He moved to one side and just then heard the loud humming of the equipment again.

That was all he had wanted to find out. One of them stood at the door while the other one worked the power dial when his way was clear to do so.

Art drew back but thought he could sense that the alien by the door didn’t follow him. Now he felt more sure of himself. Not too hurriedly, so that he would arouse no suspicion, he moved toward the small metal cabinet next to his control console. No one stopped him from opening its door. His hand darted swiftly inside and his fingers closed around a cool piece of plastic metal. He suddenly jerked the heavy thermo beamer out and turned, ready to fire.

The cold metal against him and the weight of the raygun gave him a feeling of having the upper hand. He didn’t know if these phantoms would be sensitive to the concentrated energy of a thermo shot. The field around them might protect them from any kind of radiation but the beam of this kind of weapon also packed a wallop in terms of the transmitted mechanical energy. It was like a lightning bolt in a storm. If it didn’t burn the thing it hit it would at least knock a hole in it.

Art knew they would observe him but perhaps they didn’t know what he was holding in the crook of his arm. He approached the power control for the third time, walking carefully one step at a time while watching for the right moment. He had to know exactly where the alien was standing. With his finger on the trigger he sort of listened with an instinctive ear in order not to miss the slightest warning. Step by step he came closer to the distributor box. It almost seemed as if they were not going to hinder him this time. Clutching the weapon tightly in his right hand, he reached out with his left hand toward the control dial.

Then he sensed it!

The alien came at him from the left and behind him at an angle. Art swung the heavy barrel of the beamer around and pressed the trigger automatically.

A brilliant sharp beam of energy darted from the muzzle of the weapon. He saw it split close in front of him and bend in two streams to the right and left as though it were going around an obstacle. So he hadn’t been wrong. The field around the aliens also made them insensible to the effects of a thermo gun—except for the physical impact. He could see that the point where the beam parted was receding from him. His instinctive sense of having someone close to him faded as the invisible alien was pushed back farther by the impact of the beam.

Art released his finger from the trigger when the stranger was about 5 meters back from him and then he turned swiftly and with his left hand he reset the power dial. While so doing, he held the weapon ready in his right arm.

Now his way was free because he knew what his weapon was able to do. He didn’t take any more time to search for instinctive signals of warning be cause the approximate location of his second opponent was known to him. He pressed the trigger and fanned the brilliant beam widely next to the exit hatch.

In the blinding flood of energy there was suddenly a blank spot like a hole. The beam was parted again and was going around the obstruction created by the protective field that enclosed the alien. Art tightened the beam and kept the weapon aimed at the hole. Immediately the powerful thrust repelled the unseen enemy. The apparent "hole" moved to the bulkhead wall beyond the hatch door and then swerved to the right into the middle of the Com Room.

Art had to turn to keep his opponent under fire while he backed toward the exit. The beam’s impact kept pushing the alien farther from him. The latter could no longer keep him from going out into the passage to yell for help. He heard the hatch behind him start to open. The blinding flood of energy still spewed forth from the barrel of his weapon. It was set on short range so that it would not damage the instrument consoles along the opposite wall. The air began to get heated. Successive waves of heat beat against him and he knew it was time to get out of the place.

The blue-white illumination from the corridor fell into the room as the hatch slid completely open. Art stepped back. He released the trigger of his weapon and prepared to run. He had to get to the main control room and let Eric Furchtbar know what was happening down here.

But suddenly they were all around him. Not just two as before but this time at least a dozen of them. They came striking in at him from all sides. He tried to raise his weapon again but hard blows struck against the barrel and Art had to drop it. He figured that if that was gone at least he could use his fists. So he began to swing out. It wasn’t any task to guess where his enemies were. They were everywhere around him. Where the devil had they all come from and how had so many of them managed to get on board the BOB 21?

Nevertheless, here they were, and Art soon perceived that he was be coming exhausted. They were pummelling him from every direction. Mean while, he kept on shouting everything he knew about them. Somebody had to be somewhere nearby, one of the crewmen who would hear him and under stand. All through it he kept striking blows to his right and left ahead and behind, and above and below. He even kicked out with his legs to defend himself more effectively.

But he was expending his strength. After a while that seemed like hours he was too weak to even clench his fists anymore. He flailed about him with open palms, and finally he couldn’t even raise up his arms.

He stood there defenceless and they must have seen their opportunity. A blow landed simultaneously on his chin and his neck. Art fell to the deck, at last depleted of all his frenzied violence and rage.

*

Eric Furchtbar wasn’t alerted until somebody reported that he had heard some wild shouting in the main M-Deck corridor. He sent down an orderly to see about it and minutes later he learned that Art Cavanaugh had been found unconscious. His face was swollen as though he’d been heavily beaten and he was bleeding from various wounds.

Eric knew that Art had been on duty alone in the Com Room. He had transferred Ken Lodge and Warren Lee to other posts. As long as the Com Room was manned, the operator there had direct control over the equipment. Eric had no idea of what could have happened to Cavanaugh in the meantime. He threw in a switch that channelled the IFPM portion of the Corn Room equipment into the main performance monitor. It was a routine move. He hadn’t been hoping merely with that to find out anything about Art.

But he quickly saw what had happened. The only thing left in the Com Room that showed any functional activity was the power distribution box. But it really wasn’t distributing anymore. It was just a channel now for one tremendous current, which was going somewhere that his instruments weren’t indicating.

Eric sent a detail of 4 men down to the Com Room and also ordered Doc Johannesson to look after Cavanaugh. The 4 men later reported that all equipment was knocked out in the Com Room and that somebody had turned up the main power to maximum. Eric told them to cut off the power, which was done immediately.

He kept watching his own indicators, expecting the straining needles on his meters to drop back to the normal range" but this they failed to do. They remained trembling against their top pins, still registering a tremendous flow of current. For only a few seconds, Eric was at a loss to explain it but then he began to see what was going on. He knew his station well enough to know what one would have to do to put a master circuit out of commission.

They had been able to turn on a full power source from the Com Room, and while they held the dial open they had made sure also that the generators in the power room didn’t stop working. The circuits controlled by the dial in the Com Room were no longer intact. It didn’t matter now how you set the dial there—somewhere the invisibles were now able to tap off the maximum power they needed.

Needed? For what?

He asked himself the same question that Art Cavanaugh had brought up a while before but he didn’t lose any time over it. He ordered the 4-man team to remain in the Com Room and then sent 10 more men to the generator section. He ordered them to arm themselves and to shoot at anything that moved down there. The generator room wasn’t manned at present so there was no risk in giving such a command. If there were anyone down there it would be the aliens. And Eric did not intend to have any more patience or consideration for the enemy.

Like the Com Room detail the 10-man group was equipped with wrist telecoms which were constantly in contact with the main control room. In spite of his broken arm, Lt. Hynes had insisted on leading the latter group. And Eric had let him go because he wasn’t sure where he was going to get all the men he needed at the moment.

On the way to the power room everything was quiet. If there were any aliens in the station’s corridors and companionways, they did nothing to hinder Ed’s force of men. Unmolested, the 11-man detail reached the lower deck and the big room where the powerful generators of the BOB 21 were located. This was the main power source of the station.

Ed Hynes’ wrist device transmitted a clear picture of the large room. Eric was able to observe it on his smaller telecom screen. He could see that the indicator lamps on the control panels were all green, signifying that everything was in order. Hynes let his pickup device scan the whole installation and everywhere was the same scene of order and calm.

"Alright, Ed," cut in Eric in a gruff tone. "shut down the Com Room’s generator."

After Hynes confirmed the order, Eric saw him go with one of his men between the towering machines until he finally stopped in front of one of them. He looked around him cautiously. The man next to him held his weapon ready to fire. Hynes lifted his good arm and reached out his hand to the switch lever.

That’s when things went wrong.

Eric couldn’t see clearly what happened. He was only aware that Ed Hynes suddenly flew to one side. His companion swung around and fired, even though he couldn’t see anything more than Eric, who was now leaning close to his screen. But Eric’s eyes widened incredulously as he watched the flaming bright beam of the thermo weapon and saw it make what looked like a hole in nothingness, as if the flow of electromagnetic energy were flowing around an obstruction. He could see that the hole started to recede from the muzzle of the weapon, at first slowly and then faster. He caught on to what was happening as quickly as Cavanaugh had, a half hour before.

The invisibles were there! The thermo gun’s energy beam couldn’t do anything to them, or at least not in the normal way. But the beam also exerted mechanical force. Meanwhile, Ed Hynes had gotten onto his feet again. He shoved his companion aside and again reached for the power switch. This time he was able to grasp it but he didn’t get to pull it down to a shut off position. A number of things happened simultaneously. Hynes was flung to one side and his companion, who was still firing his weapon, suddenly let out a cry and dropped to his knees. The scene was still being transmitted by wrist telecoms among the other men in the background. Now Eric saw them charging forward to help the other two. He caught a glimpse of some of their faces which were grim with anger. They all held their weapons out in front of them and several were already firing. A hissing flood of hot energy shot out ahead of them. They all looked as if they could handle a superior enemy force in a matter of moments.

But after only a few steps they crashed into a wall. Or at least it looked as if there were a wall there. The brilliant ray beams were now being deflected upward and downward, causing part of the awful heat to reflect back against the attackers. They did not realize soon enough that an obstacle had been thrown in front of them and most of them crashed into it, some falling down and others jumping back.

Eric knew that his men needed him down there. He had already unmanned half the station to halt the activities of the aliens.

Without a word, the duty corporal who had been resuscitated by Johannesson took over his position at the main console. Eric opened a small safe near his chair and extracted a lightweight disintegrator.

Leaving the control room, he ran along the main corridor of the central deck to the antigrav shaft. When he leapt into it he gave himself a shove from the shaft wall to accelerate his descent. He hit the bottom fairly hard but took up the shock by bending his knees. Now in the lower passage he could hear the sounds of the conflict. The power room was to his right. He set his weapon ready for firing and ran to the open hatchway. He wasn’t prepared for the heatwave when he entered and for several moments it took his breath away. When he saw his men sprawled on the deck, however, anger drove him forward. The men turned to see their commander charging through the bulkhead opening into the room.

Eric came in firing. He didn’t see anything to shoot at but he instinctively pressed the trigger, blindly rushing pell-mell into the fray. The pale green ray of the disintegrator pistol was sweeping back and forth, close over the heads of the men on the floor. He had no idea whether or not he would hit something but he was making every effort to do so.

A series of shrill, deafening cries filled the room, horribly strange and alien. For only a second or so, Eric was confused, aiming his concentrated beam at a specific point. Then he set the beam to fan out wider and let it sweep across everything ahead of him. He was aware of his disadvantage in the face of the enemy, who could see him when he couldn’t see them. They would try to prevent him from firing. Apparently the disintegrator was more capable of harming them than the thermo guns.

He was about to turn to the men and yell out an order to arm themselves with disintegrators when the first blow struck him. One of the invisibles had crept up behind him and he was hit on the head. He staggered to one side but immediately caught himself from falling. He swung about swiftly and directed the green energy beam at the spot where the blow had come from.

A wild cry almost deafened him. There was a flash before him of some thing formless and incomprehensible and a wave of suffocating heat swept back upon him. But he felt a surge of triumph. He had managed to knock one of them out of action! The disintegrator had destroyed the alien’s protective screen.

He was suddenly sobered by a second attempt on the part of one of the intruders. The blow only grazed him and he swung about and fired where he thought the enemy might be. But the invisible appeared to have been warned because no outcry followed. He had dodged out of the way. A second later Eric was struck from another direction and this time he was really knocked to his knees.

It cleared his mind, however, to one reality. He realized there was no hope of winning against these odds.

He retreated slowly, fanning the width of the room with his beam. Hynes and his helper had joined the others by now as evidently the unseen wall of force was gone. Eric had the gun set for minimum but in spite of this the cabinet panels protecting the generators began to show a rising mist of molecular gas. In a few moments the cover casings would shatter and collapse. There was no purpose to this, Eric decided. He and his men were simply Fleet personnel. Nobody had ever prepared them for a battle with invisible aliens from another galaxy. All they were supposed to do was run a picket post out here and advise the Earth of any unusual occurrences. It wasn’t intended that they should be an advance fighting force against aliens.

There were other men for that. The men of Division 3—Nike Quinto’s specialists!

Eric turned around. "Get the transmitters ready!" he yelled to the man nearest him.

The man was startled but he turned and ran to the exit hatch.

Eric tried to hold his position. He was sure the man had understood his order. They would fire up the transmitters. In every room of the station the blue signal lights would announce that the transmitters were on, and everybody would know what the situation had come to. Each man would go as quickly as possible to the transmitter station and get himself to safety, each in his turn.

It was necessary to hold out here to keep the invisibles from being aware of the retreat plan. Eric’s right arm had become numb. He transferred the disintegrator to his left hand and continued firing. Automatically, his hand weaved back and forth to keep the beam fanning as wide a cross-section of the room as possible. Behind him the men were slowly backing out. They understood that the station was being abandoned. Under Eric’s covering fire they carried the unconscious men with them.

Eric was streaming sweat. The heat in the room was almost unbearable. The air seemed to shimmer before him. The way behind him was clear now as he backed away. There was no sense in trying to hold out here any longer. He tried to see if the aliens would pursue him outside into the corridor. He still had to fight off their blows at the hatch door but as soon as he got into the outer passage they left him alone. He fired a last salvo through the opening and then ran as fast as his legs could carry him.

In the transmitter station everything was in full operation. There were two cage-like compartments which were transporting one man after another from the BOB 21 to the Joann. The badly wounded had been the first to be sent through. Meanwhile, Art Cavanaugh had recovered and was there as tirelessly busy as ever, standing in front of the sender cages and checking off each man as he made the jump.

He saluted when he saw Eric. "Just these last two men here, sir" he said briskly. "then there’ll be just you and me."

Almost at the same moment the two transmitter cages emitted a loud buzzing sound. Green indicators flashed. The cages were ready for the next transmission. The two men Art had indicated yanked open the doors and sat down on the uncomfortable waiting benches. Art deftly closed the outer wire doors. Then he adjusted the power controls and pressed two release buttons. The buzzing stopped, to be replaced by a new sound that was like the rumbling of an old-fashioned freight truck. Absently, Eric saw a faint mist fill the two cages. When the mist vanished after a second or so, the two men were no longer there.

Art Cavanaugh politely opened the doors again when the green lights flashed on. "If you please, sir!"

Eric refused. "You first, Sergeant!" he said wearily, and he managed a slight smile. "The captain leaves his ship last."

Art obeyed silently. He stepped into one of the compartments and closed the grid door behind him. Eric handled the controls and in a few seconds the next to last man on board the BOB 21 disappeared.

Eric had remained last for a reason. An idea had suddenly occurred to him. He didn’t intend to give up the BOB 21 permanently. The return here was only a matter of time, so the transmitters would still be needed. But what if the enemy had gotten in here in the meantime and managed to observe how they worked? Would he use them to his own purposes, which would obviously be opposed to Terran interests, or would he simply destroy the equipment if he didn’t know how to to use it?

Eric wanted to be sure. He took up a position with his back to the cage that Art Cavanaugh had just vanished from. For the last time he raised his weapon, set the beam for a wide fanout, and pressed the trigger. The pale green rays spewed forth from the stubby barrel. Eric made a slow sweep with his hand - and hit.

There was a brilliant flash next to the closed bulkhead door, followed by a strange cry that reverberated in the room. Eric charged forward immediately. Somehow it seemed impossible to him that more than one of the aliens had gotten into the transmitter room. The hatch had not opened since he had arrived.

Without using any particular tactic, he threw himself at the spot where the flash had occurred, although the cry had ceased. He collided with something soft and yielding. He couldn’t see anything but something was there between him and the wall by the door.

He tried to grasp it and although he touched the unseen creature his fingers slipped off of it. As the phantom thing sought to elude him he aimed his fist at a place which would have been the solar plexus of an ordinary man. There was no resulting sound nor did it seem to have any effect on the alien. He slipped out of Eric’s hands and he had to resort to his weapon again.

This time he knew exactly where to aim. With a light pressure of his finger he changed the focus of the beam and fired. This time a fine, brilliant green needle of energy shot from the muzzle.

Eric had expected the effect of the disintegrator to be greater than before but he wasn’t prepared for what happened then.

Something exploded in front of him with a thunderous roar. He was struck by a wave of highly compressed air and he was thrown to one side. A brilliant flash blinded him in the midst of an echoing loud cry. He landed against the wall and slid to the floor. The impact knocked the wind out of him so that he lay there with coloured lights dancing in front of his eyes while he tried to regain his strength.

It was then that he saw the alien. The devastating shot had caused his screen to break down, or at least it had weakened it considerably. What Eric could see was anything but clear and definite. Either the stranger’s screen was still partially working or Eric’s vision hadn’t quite recovered yet.

It was hardly more than a shadow. As it moved swiftly across the room, Eric could not make out any definite shape to it. It was just a constant flowing and gliding apparition. In a second or so it reached the wall by the door where Eric had nailed it before. For just an instant he saw the thing silhouetted in a blue-white shimmering light - and then it vanished.

There could be no doubt that it had exited the room in a way that was normal for its kind - through the solid wall.

Breathing heavily, Eric got to his feet. It was clear to him that he had missed his mark. The alien had gotten away. But if he were capable of understanding Terran technology, then he would know what the two grid cabinets were used for. And of course he’d report this to his companions. They would come here and want to use the transmitters for their own purposes.

Eric decided that he could not allow it to happen. He and his men needed the equipment for themselves. So he resolved to remain on board the BOB 21.