n.

The hiss of the releasing clutch came softly to him as the free-signal
flashed, and he sank back with a great sigh of relief as the motors
hummed and the blades above leaped into action. Then the stern blast
roared, though its sound came faintly through the deadened walls, and
he sent the little speedster for the pale blue light of an ascending
area. Nor did he level off until the gauge before him said twenty
thousand.

His first thought had been for their own safety in the air, but with
it was a frantic desire to reach the great plant of the Harkness
Terminals. What had happened there? Had there been any damage? Had
they felt the shock? A few seconds in level twenty would tell him. He
reached the place of alternate flashes where he could descend, and the
little ship fell smoothly down.

Below him the great expanse of buildings took form, and they seemed
safe and intact. His intention was to land, till the slim hands of
Chet Bullard thrust him roughly aside and reached for the controls.

It was Bullard's right--a master pilot could take control at any
time--but Harkness stared in amazement as the other lifted the ship,
then swung it out over the expanse of ocean beyond--stared until his
own eyes followed those of Chet Bullard to see the wall of water that
was sweeping toward the land.

Chet, he knew, had held them in a free-space level, where they could
maneuver as they pleased, but he knew, too, that the pilot's hands
were touching levers that swung them at a quite unlawful speed past
other ships, and that swept them down in a great curve above the
ocean's broad expanse.

* * * * *

Harkness did not at once grasp the meaning of the thing. There was the
water, sparkling clear, and a monstrous wave that lifted itself up to
mountainous heights. Behind it the ocean's blue became a sea of mud;
and only when he glanced at their ground-speed detector did he sense
that the watery mountain was hurling itself upon the shore with the
swiftness of a great super-liner.

There were the out-thrusting capes that made a safe harbor for the
commerce that came on and beneath the waters to the Harkness
Terminals; the wave built itself up to still greater heights as it
came between them. They were riding above it by a thousand feet, and
Walter Harkness, in sudden knowledge of what this meant, stared with
straining eyes at the wild thing that raced with them underneath.

He must do something--a