st ship had passed through;
the planes that daily maneuver over it had returned to their hangars;
the men who shepherd ships through the locks had gone either to bed or
to Panama City or Colon. The Canal, as always at night, seemed almost
deserted.

To Chris, clutching tight to his hazardous perch, it looked utterly
deserted. The ride had been nightmare-like, fraught every second with
peril. Several times the whip of wind had come near tearing him loose;
the cold air of the upper layers had numbed his fingers, his whole
body; he was chilled and, experiencing the inevitable let-down which
comes after a great effort, miserable. Just then, the task ahead
appeared well-nigh impossible.

The only thing in his favor was that Kashtanov apparently did not know
he was aboard, since the plane had flown evenly, steadily, not trying
to shake off the man hanging to its landing gear by somersaulting in
the sky. Evidently the jolt as it was rising hadn't warned the unseen
pilot; the fog from the broken machine had obscured Chris's wild leap.

But what, he thought, of that? The element of surprise was in his
favor--but how to gain advantage by it? He had no weapon, nothing save
bare hands with which to subdue a foe as elusive as the wind that was
now hurtling by him. Clinging there, slipping now and again, drenched
with cold, the odds looked hopeless.

Then, suddenly, the booming of the main motor stopped. Only a quiet
purring from the wings took its place. The helicopter-plane hovered
almost motionless, quiet and deadly like a sinister bird of prey. It
began to drop straight down through the dark. Chris Travers glanced
below.

* * * * *

There, misty, fainty, small as the toy of a child, lay Gatun Dam, with
the spillway in its center.

Chris stared. So small the dam looked--this dream of an engineer, this
tiny outpost of man's genius thrust boldly into the breast of the
tropics, holding back a whole lake with its cement flanks, enabling
ocean to be linked to ocean! It was the heart of the Canal; if burst,
the veins would be drained.

Something that cannot be caught in words seemed seize the lone
American then. As in a trance, he saw more than the dam; he saw what
it symbolized. He saw the Frenchmen who had tried to thrust the Canal
through first, and who had failed, dying in hundreds. He saw the men
of his own race who had carried that mighty work on; saw them gouging
through the raw earth and