en who accompanied him. We'll have to
chance recognition; but at least there's no difference in the suits
we're wearing, and we'll clasp our glasses on all the way to the lock,
for surely Dr. Ku has to use some similar device. Keep your faces
averted as much as you can though, when near, and your rayguns in your
belts. If there's to be gunplay, leave the first shot to me. You'll
both follow me just as those two followed Dr. Ku."

Ban Wilson asked: "Will you go down into the valley between the trees,
then up the face of the rock? The guard wouldn't see us until we were
right at the lock."

"No, he wouldn't: but he'd wonder why Ku Sui was being so cautious.
We'll go straight across, in full view. We'll get in easily, or--well,
that depends. Ready?"

They fastened the glasses over their eyes, keeping the helmet
face-plates partly open. The rayguns they eased in their belt
holsters, and slid back the hinged palms of their mittens, to give
exit if need be to their gun-hands. They were ready.

Switching on the helmet gravity-plates to swift repulsion, the three
soared out of the trees, soared up on a straight, inclined line for
the dome on the asteroid, a steady, rapid climb that soon raised them
one mile, a second and a third, where they leveled off and sped
straight ahead. Now they could look right into the dome.

Rapidly the port-lock that was their objective grew in size. Behind it
were the buildings: the large, four-winged central structure and the
supplementary workshops and hangars, coolie-quarters and outhouses,
all dim and shimmering through the infra-red--the mysterious, lonely
citadel of Dr. Ku Sui. There it all was, inside the dome, with the
rest of the asteroid looming massive behind.

A quarter-mile away, and swiftly half that, and half again the three
grouped figures arrowed ahead without hesitation. And the Hawk said
curtly:

"I see no men--do either of you? It looks deserted."

"There!" cried Ban, after a second. "There! Beside the port-lock. Just
now!"

* * * * *

Beside the smaller port-lock's inner door a figure had appeared, clad
in the neat yellow smock of a servitor of Ku Sui. It was a smooth,
impassive Oriental face that turned to stare out at the approaching
men; and even Ban knew that this sentinel stationed at the lock was
one of the coolies whose brains Dr. Ku had altered, turning him into a
mechanicalized man who obeyed no orders but his. He watched clos