door swung shut behind. On the
pressing of another button there sounded a gurgling and splashing of
water, and quickly the chamber was filled. The air-car was now a
submarine. All these operations were effected by radio control from
within it.

When the water filled the inside of the chamber, the second door
opened automatically, and the car started forward through a long
steel-lined, water-filled tube. It continued on even keel until Carse,
watching through the bow window, saw a red light flash in the ceiling
of the tube: and then he tilted the car and rose.

A second later, the shiny, water-dripping shape of the car broke
through the surface of the lake that edged on the hill, and forsook
the water for the air.

To an outside observer, the appearance of the air-car and its
subsequent movements would have been incomprehensible. There lay the
hill, desolate, barren, apparently lifeless: and there, washing
against its slopes, the lake; nothing more. Then suddenly a curve of
gleaming steel thrust up through the muddy water, rose swiftly almost
straight into the cloudless blue of the sky, and as suddenly
disappeared, and remained gone from sight, as if the ether had opened
and swallowed it.

* * * * *

Using his infra-red device, Carse brought the car in neatly through
the ship-size port-lock of the dome, and sped it across to the
central building, to land lightly beside one of the wings. Debarking,
he ran down the wing's passage and in a few seconds was back in the
asteroid's control room.

Friday was sitting in a chair close by the bound Eurasian; Ban Wilson,
more restless, was pacing up and down. The Hawk nodded in response to
their looks of welcome and issued curt orders.

"All ready. Ban, the air-car's just outside; go over and get those
four men and the coolie and put them in it. Have your raygun ready,
but don't use it if humanly possible. We're going down to the
laboratory. I want speed. Please hurry."

"Right Carse!"

"Friday," the Hawk continued, "help me untie Dr. Ku."

They stooped to the chair and the impassive, silken figure sitting in
it, and in a moment the bonds were ripped off; all save those on the
wrists. Stretching himself, the Eurasian asked:

"You are taking the brains down now, Captain Carse?"

"No--just you, your assistants and that one coolie, this trip. Master
Leithgow and I wish to have a talk with you."

"I am always agreeable, my friend."

"Y