Bomba crouched beneath the shelter of an overhanging rock, straining his ears for a faint sound not born of the storm.

The rain was coming down in a pitiless torrent. The thunder battered against the surrounding hills and went off grumbling into the distance, to be swallowed up in louder detonations. Trees bent before the fury of the wind like a bow in the hands of an archer. Some of the smaller trunks, wrenched from their roots, fell with a thud to the ground. Castanha nuts, like pebbles from the sling shot of a giant, pelted the jungle in a deadly hail. It was a devastating storm that for the time subdued all other forces of the jungle.

None but the ears of the boy of the jungle could have detected that faint sound through the clamor of the tempest. None but the eyes of Bomba could have seen that something that stood out like a black blot against the vivid background of the lightning.

Bomba crouched lower beneath the jutting rock and one hand slipped to the belt at his waist, firmly gripping the handle of his razor-edged knife. Whether man, beast or reptile threatened, Bomba was not to be caught off his guard.

A crash of thunder that seemed to rip the very heavens asunder, a flash of lightning like a jagged finger of fire searing the sky, and again Bomba saw that blot, but this time more distinctly.

With a smothered exclamation, Bomba slipped into the narrow gully that ran behind the rock, a gully, now half filled with water but thickly fringed with bushes, concealing him from the eyes of his enemies.

For the flash of lightning had revealed no lurking jaguar, hungry for its prey. The foes of Bomba were of a far deadlier kind, deadlier even than the wicked anaconda with its folds of steel. For these were headhunters—bloodthirsty, cruel, cunning—bucks of the tribe of the dreaded chief, Nascanora.

The eyes of Bomba, keen as those of the big cats that stalked the jungle, had counted three of these in the brief space of the lightning flash. They stood like naked statues, each gripping a spear, the eyes of each prodding the deeper shadows beneath the overhanging rock.

Rage was in the heart of the jungle boy, and fear; fear not for himself but for Cody Casson, his one white friend who had reared him from infancy; Cody Casson, now frail and wasted, who lay helpless, perhaps close to death, in the hut of Pipina, the squaw.

Bomba knew with a sure instinct the reason for the presence of the headhunters of Nascanora, now far from their tribal abode in the shadow of the Giant Cataract. They were once more on the trail of Casson; Casson whom Bomba loved. They would try to capture him, take him to their village and torture him, and then, when death had brought an end to his sufferings, place his head on Nascanora’s wigwam.