The others were now awake — his mother, Siris, and his two younger sisters, Runa and Mara. Ulf said little within the hearing of the girls; yet they could sense that something was wrong, and their fear was like an unpleasant vibration, or a sweet-sickly smell.
From the entrance stone, Veig beckoned his father. Niall also crept to the mouth of the burrow, and before the two heads blocked the daylight he glimpsed the white balloon, moving fast over the tops of the organ cactus, more than a mile away.
Ulf said softly: “The little ones must be put to sleep.”
Veig nodded and disappeared into the depths of the burrow where the ants were stabled. Ten minutes later, he returned with a gourd full of the sweet, porridge-like substance that the ants secreted in their craws. Siris scraped portions of this on wooden platters and the girls ate hungrily, unaccustomed to such generous helpings. When Niall accepted his platter, he smelt the heavy, flowery scent of the ortis plant that came from the forest of the Great Delta. But he had no desire to sleep; he was confident now that he could control his fear reaction. To satisfy his father, he swallowed a mouthful but as soon as no one was looking, pushed the plate under a pile of alfa grass used for bedding. Five minutes later, the little girls were fast asleep again. Niall also felt a pleasant heaviness from the narcotic, a warm glow that soothed the feeling of hunger; but his mind remained alert.
Siris had waited until the girls were asleep before she ate sparingly of the honeydew porridge. Like Niall, she wanted to remain awake. But this was not so that she could help defend the burrow. It was so she could kill the children, then herself, if the death spiders detected their presence.
She was swallowing the first mouthful when the fear-probe invaded the burrow. It was literally an invasion, as if one of the enormous spiders had leapt into the midst of their underground home. For a moment, Niall almost lost control; but his mind instantly grasped that this invisible terror was bodiless and impersonal. Siris was not so lucky. Niall felt as well as saw the fear that poured out of her like a shriek. Ulf and Veig felt it too — the searching will of the death spider seemed to have some quality that amplified their feelings and also released involuntary bursts of fear. Niall alone remained perfectly controlled and calm. He had contracted his mind to a point, so the light seemed to glow inside his head, and he felt strangely detached from his surroundings and from his own personality.
The fear-probe seemed to hesitate, as if it had stopped to listen. But now all the humans had their fear under control, and the inside of the burrow seemed full of a throbbing silence. The two girls breathed peacefully. As the fear-probe faded, like a sound dying away in the distance, Niall experienced a brief glow of satisfaction. If the children had been awake, their terror would have announced their presence in waves of hysteria, betraying them to the spiders as hundreds of other human children had involuntarily betrayed their families. The juice of the ortis plant was a great blessing, even though it had cost the lives of his uncle Thorg and his cousin Hrolf. Both had been overcome by the plant and eaten. Five times more that day, the fear-probes invaded the burrow; but the minds of the human beings were still as their bodies; no echo of fear betrayed their presence. Propped against the smooth wall of the burrow, a wall made of sand grains cemented by the saliva of the tiger beetle, Niall felt as if he had been turned to stone.
As the day advanced, the temperature in the burrow rose steadily. Under normal circumstances, they would have sealed the entrance with branches and stones, and the wind would have completed the work by filling the cracks with sand. But Ulf wanted to be able to see the approach of the spider balloons; it was easier to resist the fear-probes when they were expected. So the aperture under the flat stone was left open, and the hot desert wind blew into the burrow, carrying sand that was allowed to form a carpet on the floor. The children perspired as they slept. The adults were indifferent to the temperature; tension kept them at a high level of alertness. Twice during the day, Siris brought food — prickly pears and the dried meat of desert rodents — but they ate sparingly, their eyes fixed on the strip of electric blue sky.
At mid-afternoon, Niall was keeping watch when he saw a balloon on the horizon. Minutes later, another appeared to its left, then a third to its right. Soon the sky was full of balloons — he stopped counting when he reached twenty. The sheer number made his heart contract. He hissed to the others, and they joined him, standing back a few feet from the aperture so that all could see.
Ulf said softly: “Why are there so many?”
Niall was puzzled that his father failed to see the answer. The spiders knew they were being scanned by human eyes. It must have been infuriating for the Death Lords to know that down there in the desert, their prey was watching them from some hidden shelter, and that there was no way of driving them into the open. This armada of balloons was designed to cause terror. It might have succeeded in its purpose if it had come from another direction, so as to approach unseen. But in the five minutes or so that it took the balloons to pass overhead, the watchers had time to control their fear. The wind had now risen, so the balloons passed over quickly. The fear stabbed at them for a moment, seeming to illuminate them like a searchlight beam; then it had moved on.
From his vantage point at the side of the aperture, Niall could see that the balloons were spread out in a symmetrical zigzag pattern. He knew instinctively why this was so. A solitary balloon had no chance of getting an exact bearing on its prey. Its powers of observation extended downward in a kind of cone, and unless a spider’s attention was focused on the precise point from which it received an echo, it had no way of knowing exactly where that echo had come from. It might be anywhere within a square mile. But if two spiders received the echo simultaneously, each could judge its direction, and their prey could be located at the point at which the two echoes converged. And if more than two balloons received the echo, its source would be even more obvious.
Strangely enough, this insight gave Niall a curious satisfaction. It meant that he was beginning to understand the minds of the spiders, that they no longer represented the terror of the unknown. But an instinct warned him against too much self-satisfaction.
In the late afternoon, the two children stirred. Their faces were flushed from the heat, and their throats were dry — the usual after-effect of the ortis juice. Siris gave them water, and then, as a special treat, the succulent fruit of the opuntia cactus, with its astringent flavour. After that, they were given more of the drugged porridge and fell asleep again. Mara, the youngest, breathed quickly and her long hair was damp with sweat. Her mother sat with her arm extended over her in a protective gesture. Mara was everybody’s favourite, and their protectiveness had grown stronger since they had almost lost her. Three months ago, playing among the euphorbia bushes one evening, she had been attacked by a big yellow scorpion. Niall, who had been gathering prickly pear, had heard Runa’s screams and arrived in time to see the scorpion disappearing into its lair under a rock, clutching the child’s body in its enormous pincers. The sight paralysed him with shock. He had often watched with morbid fascination as a scorpion paralysed some creature with that overarching swing of its tail, then shredded and tore the carcase with its chelicerae, the short, powerful claws below the mouth; after that, the wounds would be injected with a digestive enzyme that reduced the tissues to a liquid so the scorpion could drink them. Now his first impulse was to rush in and try to grab his sister; but the sight of that moist sting, still poised above the creature’s back, warned him that this would be suicide. He ran back to the burrow, shouting for his father. Ulf acted with the control of a man whose life has often depended on his coolness. He called to Veig: “Quick, bring fire.” It seemed an unbelievably long interval of time before Veig emerged from the burrow with a burning torch of grass. With arms full of the dry, straw-like esparto, they rushed and stumbled through the cactuses to the scorpion’s lair. This was underneath a large, flat stone. The creature was waiting for them; they could see its row of eyes gleaming in the darkness, behind the huge pincers. The torch had almost burned out; Ulf blew on it to light the esparto, then rushed unhesitatingly at the entrance to the lair. The scorpion gave its dry, menacing hiss, and retreated before the flames and the smoke. Ulf kicked the burning fragments into the lair, then gave a leap sideways as the scorpion rushed out, its sting poised to strike. The giant pincers, like those of an enormous lobster, made it clumsy compared to the man. Veig rushed forward with more burning grass, which he hurled between the pincers, swerving aside to avoid the top-heavy rush. It hissed with agony, tried to turn instinctively towards its lair, and was headed off by Ulf waving a burning torch. Niall knew what he had to do. He plunged into the lair, paused a moment amongst the empty shells of beetles, then snatched up his sister and ran with her into the daylight. The scorpion saw its prey escaping and made a rush at him; Veig jumped forward and hurled his spear between its pincers. Niall handed the cold, still little body to Siris, and turned in time to see their enemy scuttling away across the desert. Veig said later that his spear had destroyed two of its eyes.