it all
right for you to talk to me?"

"You've got passage on this ship. That means something!"

"Does it?" asked Joe.

The pilot turned in his seat to glance at Joe.

"Do you think we carry passengers regularly?" he asked mildly.

"Why not?"

Pilot and co-pilot looked at each other.

"Tell him," said the pilot.

"About five months ago," said the co-pilot, "there was an Army colonel
wangled a ride to Bootstrap on a cargo plane. The plane took off. It
flew all right until twenty miles from Bootstrap. Then it stopped
checking. It dove straight for the Shed the Platform's being built in.
It was shot down. When it hit, there was an explosion." The co-pilot
shrugged. "You won't believe me, maybe. But a week later they found the
colonel's body back east. Somebody'd murdered him."

Joe blinked.

"It wasn't the colonel who rode as a passenger," said the co-pilot. "It
was somebody else. Twenty miles from Bootstrap he'd shot the pilots and
taken the controls. That's what they figure, anyhow. He meant to dive
into the construction Shed. Because--very, very cleverly--they'd managed
to get a bomb in the plane disguised as cargo. They got the men who'd
done that, later, but it was rather late."

Joe said dubiously: "But would one bomb destroy the Shed and the
Platform?"

"This one would," said the co-pilot. "It was an atom bomb. But it wasn't
a good one. It didn't detonate properly. It was a fizz-off."

Joe saw the implications. Cranks and crackpots couldn't get hold of the
materials for atom bombs. It took the resources of a large nation for
that. But a nation that didn't quite dare start an open war might try to
sneak in one atom bomb to destroy the space station. Once the Platform
was launched no other nation could dream of world domination. The United
States wouldn't go to war if the Platform was destroyed. But there could
be a strictly local hot war.

The pilot said sharply: "Something down below!"

The co-pilot fairly leaped into his right-hand seat, his safety belt
buckled in half a heartbeat.

"Check," he said in a new tone. "Where?"

The pilot pointed.

"I saw something dark," he said briefly, "where there was a deep dent in
the cloud."

The co-pilot threw a switch. Within seconds a new sound entered the
cabin. _Beep-beep-beep-beep._ They were thin squeaks, spaced a full
half-second apart, that rose to inaudibility in pitch in the fraction of
a second they lasted. The co-pilot snatched a hand phone