hey walked down the street together,
conversing in low tones.

The Nipe waited.

Not until a fifth man stopped after he opened the door and flipped a
switch on the inside did the Nipe make any motion. Then he flexed his
four pairs of limbs in anticipation--but it wasn't quite time to act
yet.

The interior lights of the shop went out. Then the man carefully locked
the front door, setting the alarms within the shop. Then, serene in the
belief that his establishment was thoroughly protected from burglars,
he, too, went down the street.

The Nipe waited a few minutes longer before he left his observation
post. All was normal, he decided. The time for action had come.

* * * * *

The Nipe moved cautiously along the alley toward the rear of the
building that was his target. The night watchman had returned to his
cubicle, as he always did after his preliminary inspection of the
building's alarm system. He would not leave for some time yet, if he
followed his habits. And the Nipe saw no reason why he should not.

Carefully he approached the rear door of the little optical shop.

_[11]_

The two massive objects floating in space looked very much like deeply
pitted pieces of rock. The larger one, roughly pear-shaped and about a
quarter of a mile in its greatest dimension, was actually that--a huge
hunk of rock. The smaller--_much_ smaller--of the two was not what it
appeared to be. It was a phony. Anyone who had been able to conduct a
very close personal inspection of it would have recognized it for what
it was--a camouflaged spaceboat.

The camouflaged spaceboat was on a near-collision course with reference
to the larger mass, although their relative velocities were not great.

At precisely the right time, the smaller drifted by the larger, only a
few hundred yards away. The weakness of the gravitational fields
generated between the two caused only a slight change of orbit on the
part of both bodies. Then they began to separate.

But, during the few seconds of their closest approach, a third body
detached itself from the camouflaged spaceboat and shot rapidly across
the intervening distance to land on the surface of the floating
mountain.

The third body was a man in a spacesuit. As soon as he landed, he sat
down, stock-still, and checked the instrument case he held in his hands.

No response. Thus far, then, he had succeeded.

He had had to pick his time precisely. The