es," said the Hawk, "you'll be surprisingly agreeable. And truthful
and helpful, too. Now--outside, please, and do not attempt to delay me
in any way. I am in a great hurry, and consequently will not be
patient at any tricks." He turned to the Negro. "Friday. I'm leaving
you here on guard. Stay alert, gun handy, and keep in radio contact.
I'll be back soon."

"Yes, suh!"

* * * * *

Walking behind his captive, the Hawk left, passing down the wing to
the air-car outside. There, Ban Wilson was waiting with the four white
assistants of Dr. Ku and the one robot-coolie, all unarmed, stolid,
emotionless. Carse placed them all in the rear seats of the car's
compartment, Ban facing them with drawn raygun. Then with a hum from
its generators the car raised, wheeled, slid forward, until through
the large port-lock, and swooped down to the lake.

Dr. Ku Sui watched everything with an interest he did not attempt to
disguise. There was being revealed to him the secret entrance to Eliot
Leithgow's laboratory, and long had he sought for that laboratory,
long pondered on its probable location. No doubt, at various times,
pissing over, he had seen the barren hill and its flanking lake, but
had never given them a second glance. Yet here, right in the lake, was
the doorway to Leithgow's refuge!

The air-car lowered like a humming bird to the lake's surface, paused
and dipped under. The light left the sealed ports and entrance
hatchway, and the water pressed around, dark and muddy. Down the car
sunk, apparently without direction, its course very slow, until ahead,
out of the blackness, a spot of red winked.

At once the air-car made towards it and slid into the tube leading
through the hill. Quickly it was in the chamber of the lock, the outer
door closed automatically behind, the water was drained out, and then
the inner door opened and the car, dripping, emerged into the
brilliantly-lit hangar and went to rest in its mooring cradle beside
Leithgow's space-ship.

A minute later its passengers were in the laboratory of the Master
Scientist.

* * * * *

Dr. Ku Sui took in the arrangements made in the laboratory with a
swift glance, and then his eyes went to a door that opened in the
opposite wall and to the slight, smock-garbed figure that came through
it. He smiled.

"Ah, Master Leithgow! A return visit, you see. At Captain Carse's
invitation. It is very interestin