“But by theoretical calculations it has been shown that the greatest triumph of all, intelligent micro-life, can be produced in only one way; we know the needed combination of- elements, of amino acids and carbohydrates. Many times we have gathered these things and put them together in the proper way, but the stimulating spark has not appeared. We lack the one thing which will start that life working.

“The lower forms of life we have used have been stirred from inorganic immobility to life by the flashing of the rays of radium. To procure more intelligent forms, even more powerful rays are needed, and some of our best results have been attained by the aid of immense X-ray tubes operating at nearly ten million volts. But to create the ultimate ideal, intelligent, obedient, microscopic life, we must have rays emanating from a fifteen billion volt source! Rays of a particular type...

“We need it," Starn Druth explained softly, “because with intelligent, obedient life-forms of microscopic size, we can become immortal.”

Penton started. “Immortality — how?”