don't wait! You must not take chance of
being hurt. Go to your work. Call Grigory in. Go, Kashtanov!"

"I go, Istafiev."

"No, you don't!" Chris Travers croaked almost inaudibly. "_You
don't!_"

Thought of the Canal lying there defenseless, of Kashtanov speeding
towards it on his wrecker's errand, kindled within him a strength that
was unnatural, superhuman. Like a wildcat he tore loose from the
choking grip on his throat; Istafiev tried to subdue that sudden,
unlooked-for surge of power, but could not. Five piston-like, jabbing
blows crunched into him from Chris's hurtling fist, and with the fifth
Istafiev faded quietly out of the picture....

Chris sprang up and started a leap for the door he could not see. A
body brushed against him; dimly through the smoke he saw the man
called Grigory, and Grigory saw him, but not for long. A whaling swing
lifted him two inches clear of the floor, and then he went down onto
the peacefully recumbent Istafiev; and Chris Travers, fighting mad,
stormed from the hut into the clearing outside.

The camouflaged framework had been raised; soft motors were purring
helicopter propellers around and lifting a plane up towards the stars
hanging high above.

The airplane was already feet off the ground and sweeping straight up.
A sane man wouldn't have thought of it, but Chris wasn't quite sane
just then. With a short sprint, he launched himself into a flying
leap, grabbed out desperately--and felt the bar of the undercarriage
between his hands.

The plane jolted. Then it steadied; rose with terrific acceleration.
And Chris hauled himself up onto the undercarriage and clung to one of
the wheel-stanchions, breathing, hard, hidden by the fuselage from the
invisible pilot.

The clearing and the hut, with smoke billowing from it, dropped into
nothingness. The night enclosed the helicopter-plane.

* * * * *

From the air, Panama Canal at night is a necklace of lights strung
across the thin neck of land that separates sea from sea. Then, as a
high-flying plane drops lower, the beams of light loosen into widely
separated patches, which are the locks; between them the silky black
ribbon of water runs, now widening into a dim, hill-girt lake, now
narrowing as it passes through massive Culebra Cut, then widening
again as it comes to the artificial Gatun Lake, at the far end of
which stands Gatun Dam and its spillway.

Silence hung close over the Canal. The la