The spiral-disc, a visitor from distant worlds, turned out to be farther from Parus than they had expected. In the diffused light of the projectors they had not judged the size of the spaceship correctly. It was a truly gigantic structure nearly three hundred and fifty metres in diameter. They had to take the cables from Parus in order to Stretch their protective system as far as the disc. The mysterious spaceship hung over the travellers like a vertical wall, stretching high over their heads and disappearing in the speckled sky. Jet-black clouds massed around the upper edge of the giant disc. The hull of the vessel was covered in some green substance the colour of malachite; it was badly cracked in places and proved to be about a metre thick. Through the cracks gleamed some bright, light-blue metal that had turned to a dark blue in places where the malachite covering had been rubbed off. The side of the disc facing Parus was furnished with a protuberance that curved in a spiral fifteen metres in diameter and some ten metres thick. The other side of the disc, the side that was lost in the pitch darkness, was more convex, like a section of a sphere attached to a disc twenty metres thick. On that side also there was a spiral protuberance that looked like the end of the spiral pipe emerging from the ship.
The edge of the gigantic disc was sunk deep into the ground. At the foot of this metal wall the explorers saw that stones had melted and flowed away in all directions like thick pitch.
They spent many hours looking for some sort of entrance or hatch. Either it was hidden under the malachite paint or dross or the ship’s hatches closed so neatly that no trace of them was left outside. They could not find any orifices for optical instruments or stop-cocks for any sort of blast. The metal disc seemed to be solid. Erg Noor had foreseen such a possibility and had decided to open up the ship with an electro-hydraulic tool capable of cutting through the hardest and most viscous covering of the terrestrial spaceships. After a short discussion they all agreed that the robot should open the tip of the spiral. There should be a hollow space there, a pipe or a circular gangway leading round the ship, through which they hoped to get into the ship without the risk of running into a number of bulkheads that would bar their way.
The study of the spiral-disc would be of great interest. Inside this visitor from distant worlds there might be instruments and records, all the furniture and utensils of those who had brought the ship through such expanses that, in comparison, the journeys made by terrestrial astronauts were nothing but timid sallies into outer space.
On the far side of the disc the spiral came right down to the ground. A floodlight and high-voltage cable were taken there and the bluish light that was reflected from the disc was dispersed in a dull haze spreading across the plateau as far as some high objects of indefinite shape, probably cliffs, in which there was a gap of impenetrable blackness. Neither the pale reflected light of the hazy stars nor the floodlights gave any feeling of ground in that black gap; it was probably a steep slope leading down to the lowland plain that had been seen when Tantra was landing.
With a low, dull growl, the automatic car, loaded with the only universal robot on the ship, crawled towards the disc. The unusual weight did not make any difference to the robot and it moved quickly to its place beside the metal wall: it resembled a fat man on short legs, with a long body and a huge head that leaned forward menacingly.
The robot was controlled by Erg Noor; in its four front limbs it raised the heavy cutter and stood with its legs placed firmly apart ready to begin its dangerous undertaking.
“Only Kay Bear and I will direct the robot since we are wearing high-protection suits,” said the commander in the intercommunication ‘phone. “All those in light biological spacesuits will go farther away.”
The commander hesitated. Something penetrated into his mind causing inexplicable anguish and made his knees weaken under him. The proud will of man had wilted away and given place to the dumb obedience of an animal. Sticky with perspiration from head to foot, Erg Noor, with no will of his own, strode towards the black gap in the darkness. A cry from Nisa that he heard in the telephone, brought him back to his senses. He stood still, but the power of darkness that had taken control of his psyche again drove him forward.
Following the commander, halting and obviously struggling with themselves, went Kay Bear and Eon Thai, who had been standing on the fringe of the circle of light, Away out there, in the gates of darkness, in the clouds of mist, there was a movement of weird forms beyond the comprehension of man and, therefore, the more awe-inspiring. This was not the now familiar jellyfish-like creature — in the grey half-light there moved a black cross with widely outstretched arms and a convex ellipse in the middle. Three points of the cross had lenses on them reflecting the light of the flood lamp that scarcely penetrated the misty, humid atmosphere. The base of the cross was invisible in the darkness of an unilluminated depression in the ground.
Erg Noor, who was walking faster than the others, drew near the unknown object and fell to the ground about a hundred paces away from it. Before the stupefied onlookers could realize that it was a life and death matter for their commander, the black cross had risen above the ring of cables. It bent forward like the stem of a plant and clearly intended leaning over the protective field to get Erg Noor.
Nisa, in a frenzy that lent her the strength of an athlete, ran to the robot and started turning the control levers at the back of its head. Slowly and somewhat uncertainly, the robot lifted the cutter. Then the girl, afraid that she would be unable to work the intricate machine, jumped forward and with her body covered the commander. Serpentine streams of light or lightning came from the three points of the cross. The girl fell on Erg Noor with her arms spread out on either side. Fortunately the robot had by this time turned the funnel of the cutter, with its sharp instrument inside, towards the centre of the black cross. The thing bent convulsively backwards, seemed to fall flat on the ground and then disappeared in the impenetrable darkness under the cliffs. Erg Noor and his two companions immediately recovered, lifted up the girl and retired back behind the disc. The others had by this time recovered from the shock and were wheeling out the cannon improvised from a planetary motor. With a savage ferocity such as he had never before experienced. Erg Noor directed the destructive radiation beam to the cliffs with their gate-like gap, taking special care to sweep the plain without missing a single inch. Eon Thai knelt on the ground in front of the motionless Nisa, calling her softly in the telephone and trying to get a glimpse of her face through the silicolloid helmet. The girl lay dead still with her eyes closed. No sound of breathing could be heard in the telephone nor could the biologist detect it through the spacesuit.
“The monster has killed Nisa!” cried Eon Thai bitterly, as soon as Erg Noor approached them. It was impossible to see the commander’s eyes through the narrow slit in the high-protection helmet.
“Take her to Louma on Tantra immediately.” The metallic note resounded more strongly than ever in Erg Noor’s voice. “You, too, help her find out the nature of the injury. The six of us will remain here and continue the investigation. The geologist can go back with you and collect specimens of all the rocks between here and Tantra, we cannot remain on this planet any longer. Any exploration here must be carried out in high-protection tanks but if we go on like this we’ll only ruin the whole expedition! Take the third car and hurry!”