Ken lay full-length in the padded body compartment, his feet resting on the controlling bars of the directional planes, hands on the torpoon's engine levers. A harness was buckled all around him, to keep him in place. His gray eyes, level and sober, peered through the vision-plate at the outer catapult door.

Suddenly a spot of red light glowed in it; the door quivered, swung out. A black tide swirled into the chamber. There came the hiss of released air-pressure, and the slim undersea steed rocketed out into the exterior gloom, her light-beams flashing on and propeller settling into a blur of speed as she was flung.

Ken turned on her full twenty-four knots, zoomed above the dark bulk of the slower mother ship, whose light-beams flashed across him for a second, and then straightened out in a long, slight-angled dive after the great black bodies ahead.

Aware that some strange enemy was on their track, the killers had become panicky and were darting away at their full speed, which was only slightly under that of the torpoon's humming motors, and which at times even surpassed it. Ken saw that it looked like a long chase, and settled his lean body as comfortably as he could.

(The torpoon)