oxidation the temperature down below had been raised. In the damp darkness of the bowels of the hills spontaneous combustion had begun.
The great mounds of tinderlike mushroom had begun to burn very slowly, quite unseen. There had been no flames because the hills' surface remained intact and there was no air to feed the burning. But when the army ants dug ferociously for fugitive small things, air was admitted to tunnels abandoned because of heat.
Then slow combustion speeded up. Smoulderings became flames. Sparks became coals. A dozen columns of fume-laden smoke rose into the heavens and gathered into a dense pall above the range of purple hills. And Burl apathetically watched the serried ranks of army ants march on toward the widening furnaces that awaited them.
They had recoiled from the river instinctively. But their ancestors had never known fire. In the Amazon basin, on Earth, there had never been forest fires. On the forgotten planet there had never been fires at all, unless the first forgotten colonists tried to make them. In any case the army ants had no instinctive terror of flame. They marched into the blazing openings that appeared in the hills. They snapped with their mandibles at the leaping flames, and sprang to grapple with the burning coals.
The blazing areas widened as the purple surface was consumed. Burl watched without comprehension—even without thankfulness. He stood breathing more and more easily until the glow from approaching flames reddened his skin and the acrid smoke made tears flow from his eyes. Then he retreated slowly, leaning on his club and often looking back.
Night had fallen, but yet it was light to the army ants. They marched on, shrilling their defiance. They poured devotedly—and ferociously—into the inferno of flame. At last there were only small groups of stragglers from the great ant-army scurrying here and there over the ground their comrades had stripped of all life. The bodies of the main army made a vast malodor, burning in the furnace of the hills.
There had been pain in that burning, agony such as no one would willing dwell upon. But it came of the insane courage of the ants, attacking the burning stuff with their horny jaws, rolling over and over with flaming lumps of charcoal clutched in their mandibles. Burl heard them shrilling their war-cry even as they died. Blinded, antennae singed off, legs shriveling, they yet went forward to attack their impossible enemy.
Burl made his way slowly over the hills. Twice he saw small bodies of the vanished army. They had passed between the widening furnaces and furiously devoured all that moved as they forged ahead. Once Burl was spied, and a shrill cry sounded, but he moved on and only a single ant rushed after him. Burl brought down his club and a writhing body remained to be eaten by its comrades when they came upon it.
And now the last faint traces of light had vanished in the west. There was no real brightness anywhere except the flames of the burning hills. The slow, slow nightly rain that dripped down all through the dark hours began. It made a pattering noise upon the unburnt part of the hills.
Burl found firm ground beneath his feet. He listened keenly for sounds of danger. Something rustled heavily in a thicket of toadstools a hundred feet away. There were sounds of preening, and of feet delicately placed here and there upon the ground. Then a great body took to the air with the throbbing beat of mighty wings.
A fierce down-current of air smote Burl, and he looked upward in time to glimpse the outline of a huge moth passing overhead. He turned to watch the line of its flight, and saw the fierce glow filling all the horizon. The hills burned brighter as the flames widened.
He crouched beneath a squat toadstool and waited for the dawn. The slow-dripping rain kept on, falling with irregular, drum-like beats upon the tough top of the toadstool.
He did not sleep. He was not properly hidden, and there was always danger in the dark. But this was not the darkness Burl was used to. The great fires grew and spread in the masses of ready-carbonized mushroom. The glare on the horizon grew brighter through the hours. It also came nearer.
Burl shivered a little, as he watched. He had never even dreamed of fire before, and even the overhanging clouds were lighted by these flames. Over a stretch at least a dozen miles in length and from half a mile to three miles across, the seething furnaces and columns of flame-lit smoke sent illumination over the world. It was like the glow the lights of a city can throw upon the sky. And like the flitting of aircraft above a city was the assembly of fascinated creatures of the night.
Great moths and flying beetles, gigantic gnats and midges grown huge upon this planet, fluttered and danced above the flames. As the fire came nearer, Burl could see them: colossal, delicately-formed creatures sweeping above the white-hot expanse. There were moths with riotously-colored wings of thirty-foot spread, beating the air with mighty strokes, their huge eyes glowing like garnets as they stared intoxicatedly at the incandescence below them.
Burl saw a great peacock-moth soaring above the hills with wings all of forty feet across. They fluttered like sails of unbelievable magnificence. And this was when all the separate flames had united to form a single sheet of white-hot burning stuff spread across the land for miles.
Feathery antennae of the finest lace spread out before the head of the peacock-moth; its body was of softest velvet. A ring of snow-white fur marked where its head began. The glare from below smote the maroon of its body with a strange effect. For one instant it was outlined clearly. Its eyes shone more redly than any ruby's fire. The great, delicate wings were poised in flight. Burl caught the flash of flame upon the two great irridescent spots on the wings. Shining purple and bright red, all the glory of chalcedony and of chrysoprase was reflected in the glare of burning fungi.
And then Burl saw it plunge downward, straight into the thickest and fiercest of the leaping flames. It flung itself into the furnace as a willing, drunken victim of their beauty.
Flying beetles flew clumsily above the pyre also, their horny wing-cases stiffly outstretched. In the light from below they shone like burnished metal. Their clumsy bodies, with spurred and fierce-toothed limbs, darted through the flame-lit smoke like so many grotesque meteors.
Burl saw strange collisions and still stranger meetings. Male and female flying creatures circled and spun in the glare, dancing their dance of love and death. They mounted higher than Burl could see, drunk with the ecstasy of living, and then descended to plunge headlong in the roaring flames below.
From every side the creatures came. Moths of brightest yellow, with furry bodies palpitant with life, flew madly to destruction. Other moths of a deepest black, with gruesome symbols on their wings, swiftly came to dance above the glow like motes in sunlight.
And Burl crouched beneath a toadstool, watching while the perpetual, slow raindrops fell and fell, and a continuous hissing noise came from where the rain splashed amid the flames.
4. A Killer of Monsters
The night wore on, while the creatures above the firelight danced and died, their numbers ever reinforced by fresh arrivals. Burl sat tensely still, his eyes watching everything while his mind groped for an explanation of what he saw. At last the sky grew dimly gray, then brighter, and after a long time it was day. The flames of the burning hills seemed to dim and die as all the world became bright. After a long while Burl crawled from his hiding-place and stood erect.
No more than two hundred paces from where he stood, a straight wall of smoke rose from the still-smouldering fungus-range. Burl could see the smoke rising for miles on either hand. He turned to continue on his way, and saw the remains of one of the tragedies of the night.
A great moth had flown into the flames, been horribly scorched, and floundered out again. Had it been able to fly, it would have returned to its devouring deity; but now it lay upon the ground, its antennae hopelessly seared. One beautiful wing was nothing but gaping holes. The eyes had been dimmed by flame. The exquisitely tapering limbs lay broken and crushed by the violence of landing. The creature was helpless on the ground, only the stumps of its antennae moving restlessly and the abdomen pulsating slowly as it drew pain-racked breaths.
Burl