The creature was passing directly across the entrance. It was moving so slowly that he could see it distinctly in the sharply sheared-off glow from outside the building. The glow penetrated the darkness hardly at all, but when the creature paused and half turned about even that abruptly curtailed illumination was strong enough to bring it into stark relief. He saw the monstrous shape clearly. Saw the long, insectlike legs with their tapering hairs, and the very slender, flylike body. Saw its gauzy, tightly folded wings, the metallic glitter of its immense, many-faceted eyes and the slow turning of the eyes as they sought him out in the darkness. The enormous flying insect framed for an instant in the glow was a shape of terror. It was not its size alone which was making his flesh crawl and his chest heave as his eyes remained fastened upon it in the swimming darkness. He was quite sure of that. There was something rapacious about it, a deadliness that could be instantly sensed. It seemed intent on his destruction, its enormous eyes filmed with a malignancy that made his blood run cold. Its attitude was just as terrifying, the body poised as if for attack, a rapier sharpness in the writhing mandibles, a wire-tight tension in the rhythmically vibrating thorax, the slender abdomen, and the long, hairy legs which terminated in rust-colored, cuplike disks. Loring's thoughts went into a mind-chilling whirl. The human mind does not associate ferocity with an ordinary fly. A house fly, a fruit fly, even a blue-bottle fly hovering over carrion and evoking no more than a slight, momentary shiver of disgust. But wasps and hornets are flylike in aspect and they are equally graceful in flight. Winged insects of great beauty, delicately constructed and the opposite of revolting. Yet wasps and hornets can inflict stings that can paralyze and kill. A long blue hornet in a drowsy woodland glade can be a flying torpedo, a death-dealing precision instrument, as billions of fat, sluggish caterpillars have discovered over a very long period of geologic time. And if a hornet could become large enough.... A gigantic hornet might well find a man more to its liking on an alien world, a far more delectable feast for its larvae when paralyzed with care and stored in a clay-constructed hive. Or a metal-constructed hive. The solitary wasps. The mud builders. Every schoolboy was familiar with them, every young naturalist exploring the countryside near his home, the autumn leaves turning red and yellow, the tang of woodsmoke in the air. The small, gray, skillfully cemented-over openings to their nests deep underground where unspeakable acts of insect vampirism took place. The paralyzed caterpillar shrinking, turning sere, losing its substance but remaining tormentingly alive while the gnawing, insatiable grubs waxed fat and strong. Dying in the end, its substance liquefying.... And a human caterpillar?