It was shortly after midnight when a persistent nightmare aroused Don Foster from sleep. For a moment he lay drowsily in his blankets there on the sand, with memory of the nightmare still vivid.

It had been a monstrous flying thing like a giant blue-bottle fly that he had been battling in his sleep. Memory of the thing’s high-pitched, droning buzz still rang in his ears. Then abruptly he realized that the peculiar buzzing was no mere echo of a nightmare. It was an actual sound that still vibrated from somewhere within the camp.

Startled into full awakening, Foster propped himself up on one elbow. The sound was penetrating, but not particularly loud. He was apparently the only one whom it had awakened. In the gray gloom of the desert starlight he saw the blanket-shrouded figures of the rest of the men still deep in slumber.

He realized the source of the sound now. It came from inside the black walls of Layroh’s tent, pitched there in its usual isolation on a slight rise fifty yards from the sleeping group. Foster grunted disgustedly to himself. More of Layroh’s scientific hocus-pocus! The man seemed to go out of his way to add new phases of mystery to this crazy expedition of his through the barren wastelands of the Mojave… .