"Those burns I got," shouted the pilot, staring down, "kept me awake. So
I got up and was just walking around when the call came for somebody to
drive one of these things. I took over."

Back and forth, and back and forth. From five hundred feet in the early
morning the desert had a curious appearance. The plane was low enough
for each smallest natural feature to be visible, and it was early enough
for every shrub or hummock to cast a long, slender shadow. The ground
looked streaked, but all the streaks ran the same way, and all were
shadows.

Joe shouted: "What's that?"

The plane banked at a steep angle and ran back. It banked again. The
pilot stared carefully. He reached forward and pushed a button. There
was a tiny impact underfoot. Another steep banking turn, and Joe saw a
puff of smoke in the air.

The pilot shouted: "It's a man. He looks dead."

He swung directly over the small prone object and there was a second
puff of smoke.

"They've got range finders on us from the Shed," he called across the
two-foot space separating him from Joe. "This marks the spot. Now we'll
see if there's anything to the hot part of that tip."

He reached over behind his seat and brought out a stubby pole like a
fishpole with a very large reel. There was also a headset, and something
very much like a large aluminum fish on the end of the line.

"You know Geiger counters?" called the pilot. "Stick on these headphones
and listen!"

Joe slipped on the headset. The pilot threw a switch and Joe heard
clickings. They had no pattern and no fixed frequency. They were
clickings at strictly random intervals, but there was an average
frequency, at that.

"Let the counter out the window," called the pilot, "and listen. Tell me
if the noise goes up."

Joe obeyed. The aluminum fish dangled. The line slanted astern from the
wind. It made a curve between the pole and the aluminum plummet, which
was hollow in the direction of the plane's motion. The pilot squinted
down and began to swing in a wide circle around the spot where an
apparently dead man had been sighted, and above which puffs of smoke now
floated.

Three-quarters of the way around, the random clickings suddenly became a
roar.

Joe said: "Hey!"

The pilot swung the plane about and flew back. He pointed to the button
he'd pushed.

"Poke that when you hear it again."

The clickings.... They roared. Joe pushed the button. He felt the tiny
impact.

"Once more," said