"Pipe down before you give us away," Brace growled.
The hill loomed ahead of them like a giant blot against the sky. On
their left were the thick woods where the settlers gathered timber for
fencing and bridging. Straight ahead was a deep stream, traversed by a
single bridge.
"That bridge is a likely place for a burglar alarm," Harvey said. "We'd
better swim."
They took off their clothes and left them on the bank. They let
themselves carefully down into the water and set out, using the breast
stroke to keep the oxygen apparatus out of the water. They clambered up
on the other side, chilled and shivering, and continued, naked, toward
the hill.
The ground roughened underfoot; the rise began. There was no apparent
road. Here and there stood small blighted trees, devoid of foliage,
standing like posts--They weren't trees at all! Harvey gripped Brace's
arm. "Keep away from those posts," he whispered.
They continued upward slowly. Harvey heard a faint click. He stopped.
"Hear that?" he whispered, "that click?"
Brace shook his head. They stood still, listening. There was no other
sound. Brace took a step forward, and stopped. "I heard it," he
whispered. They sank to the ground, and stretched out on their bellies,
and waited tensely.
Not a sound came out of the surrounding darkness.
Far ahead, high in the sky, the windows of Baker's castle dimly glowed
with a yellow light. There was still a long way to go.
Brace sat up and jerked a hand impatiently at Harvey. They got to their
feet and moved forward. They were moving through trees now. Harvey
followed Brace reluctantly. There was something funny. Some sound he
was hearing--or wasn't hearing--
"Red!" It was the oxygen pack. The soft, bubbling murmur it always made
was gone. "My oxygen is off! Yours, too! We've got to get back--fast!"
Brace's eyes flared white in the darkness. "Come on," Harvey shouted,
and rushed back through the trees. Brace came lumbering after him,
protesting loudly. They raced across an open space--there were the
posts again--they passed them--
Click!
And now Harvey knew where the click came from. It came from inside his
oxygen pack.
Almost instantly, he felt the soft flow of the oxygen through the
tubes. He sat down. Brace sat down heavily beside him. "Those posts,"
Harvey said. "He must have them all around the hill. They throw out
a radio wave that shuts these things off when you go past them." He
shook his head ruefully. "I should have guessed it. When I first took
a look inside this oxygen pack, I noticed something that looked like
a transistor, but I couldn't imagine what that could have to do with
oxygen."
Brace let out a long breath. "We should have kept going," he said
bitterly.
"There was a good two hours of climbing ahead of us. We'd have been
dead a long time before we got there."
"Okay," Brace said. "Let's go wreck these radio posts."
"I'm afraid he has that all figured out," Harvey said sadly. "You
notice the posts shut you off when you're going one way, and turn you
on again when you're going back. If you go over there and wreck them,
there'll be nothing to turn you on again."
Red cursed long and loud. "There must be _some_ way to beat this oxygen
racket."
"We'll think of something," Harvey said determinedly.
But the echo of his confident words rapidly faded as they moved through
the grain fields. He was tired and chilled. Think of something? That
white-haired devil in that eagle's nest had been thinking of the same
subject for a decade. Could there be any angles he had overlooked?
* * * * *
Long after Ruth was asleep that night, Harvey lay in bed thinking. He
reviewed, item by item, everything he could remember about electricity,
radiation, the laws of gases, atmospheric constituents, the mechanics
of partial pressures--all the tag-end memories of his college science
courses. He felt that if there was a solution, it had to be something
elementary, something that matched the simplicity of Baker's own idea.
The thoughts went around and around in his brain, an intricate and
dizzying dance, forming a pattern that grew fuzzier and fuzzier and
fuzzier....
He sat up with a start. His brain was tingling with something ...
something that seemed to be....
He struggled into his clothes, and dashed out of the house. He ran up
the dark road and burst into Dr. Lurie's house. "Doc, Doc, wake up!" he
yelled. "I need some scientific advice!"
Shortly after sunrise, when most of the settlers were heading for the
fields, Harvey and Dr. Lurie went to the COM booth. "Better let me do
the talking," Harvey said.
"I'd prefer it that way," Dr. Lurie said.
* * * * *
Baker, sitting before the electronic telescope, was enjoying the
sight of the great phalanx of settlers swarming into the fields, when
the buzzer sounded on his communication set. In a moment, two faces
appeared--Dr. Lurie and Harvey Flanders. They weren't wearing their
oxygen packs.
"Good morning, gentlemen," Baker said affably.
"Hiya," said Harvey Flanders.
"Well!" said Baker. "I'm certainly glad to see you in such good spirits
after last night's expedition."
"Thanks," Harvey said. "All we want to tell you is that you don't have
to send us any oxygen any more."