Before plunging into that waiting tangle where life and death carried on a visible, unceasing struggle, he hesitated. Instinctively he shrank from losing himself in that mad green world. * * * * * He had first heard of the Ungapuks at the convention of the Nescience Club in New York, that body of scientists, near-scientists and adventurers linked together for the purpose of awarding the yearly Woolman prizes for the most spectacular addition of empiric facts to various branches of science. One of the members of the club, an explorer, had told a wild yarn about a tribe of Brazilian Indians, headed by Sir Basil Addington, an English scientist, who was conducting secret experiments in biochemistry in his jungle laboratory. The explorer had said that the scientist, half-crazed by a powerful narcotic, had seemingly discovered some secret of life which enabled him to produce monsters in his laboratory and to change the physical characteristics of the Ungapuk Indians, who, in five years, had been transformed from cannibals into cultured men and women. And now Hale Oakham, hoping to win one of the Woolman prizes, was here in the country of the Ungapuks, entering the jungle path that lead to the unknown. Fifty feet from the _igarape_, the path curved sharply away from a giant tree. Hale approached the bend with his hand on his gun. Just before he reached it, he stopped suddenly to listen. A woman's voice had suddenly broken forth in a wild, incredibly sweet song. Hale stood entranced, drinking in the heady sounds that stirred his emotions like _masata_, the jungle intoxicant. The singer approached the bend in the path, while the young man waited eagerly. The first sight of her made him gasp. He had expected to see an Indian girl. No sane traveler would imagine a white woman in the Amazon jungle, with skin as amazingly pale as the great, fleshy victoria regia lilies in the _igarape_. When she saw Hale, she stopped instantly. With a quick, practiced twist, she reached for the bow flung across her shoulders and fitted a barbed arrow to the string. * * * * * She was a beautiful barbarian, standing quivering before him. In the thick dull gold braids hanging over her bare shoulders flamed two enormous scarlet flowers, no redder than her own lips pouted in alarm. There was a savage brevity to her clothing, which consisted only of a short skirt of rough native grass and breastplates of beaten gold, held in place by strings of colored seeds. The girl held out an imperious hand and, in perfect English, said: "Go back!" Hale drew his long body up to its slim height, folded his arms, and gave her his most winning smile. His insolence added to his wholesome good looks. "Why?" he exclaimed. "I've come a couple of thousand miles to call on you." He saw that the eyes which held his levelly were pure and limpid, and of an astonishing orchid-blue.