he side of a house in the ship. No air in the
engine room. Without air, we can't control the temperature. If we go
into space, the engine room temperature will drop almost to absolute
zero. These drivers are not designed to work in that temperature, and
they won't work in it. We have to land and repair the ship before we
dare go into space."

"But--"

"We land here!"

There was a split second of silence. "Okay, Jed," Nielson said. "But if
we run into another of those spheres--"

"We'll know what to do about it. Ron Val. Ushur. Back to the bridge and
man the negatron. If you see anything that even looks suspicious, beam
it."

Ron Val and Usher dived through the door that led forward.

"Stern observation post. Are you alive back there?"

"We heard you, Jed. We're alive all right."

Back of the engine room, tucked away in the stern, was another negatron.

"Shoot on sight!" Hargraves said.

The Third Interstellar Expedition was coming in to land--with her fangs
bared.

Jed Hargraves called a volunteer to hold the switch--it had to be held
in by hand, otherwise it would automatically kick out again--and went
forward to the bridge. Red Nielson gladly relinquished the controls to
him.

"The sphere crashed over there," Nielson said, waving vaguely to the
right.

* * * * *

Not until he stepped on the bridge did Jed Hargraves realize how close a
call they had had. The fight had started well outside the upper limits
of the atmosphere. They were well inside it now. Another few minutes and
they would have screamed to a flaming crash here on this world and the
Third Interstellar Expedition would have accomplished only half its
mission, the least important half.

He shoved the nose of the ship down, the giants working eagerly at their
treadmill now, as if they realized they had been caught loafing on the
job and were trying to make amends. The planet swam up toward them. He
barely heard the voice of Noble reporting a chemical test of the air
that was now swirling around the ship. "--oxygen, so much; water vapor;
nitrogen--" The air was breathable. They would not have to attempt
repairs in space suits, then.

Abruptly, as they dropped lower, the contour of the planet seemed to
change from the shape of a ball to the shape of a cup. The eyes did
that. The eyes were tricky. But Jed knew his eyes were not tricking him
when they brought him impressions of the surface below them.

A gen