iately."

He hung up, and Joe went back to his meal. He felt uneasy. There
couldn't be any way to make a jet motor explode unless you fed it
explosive fuel. Then there couldn't be any way to stop it. And
then--after the wreck had burned--there couldn't be any way to prove it
was really sabotage. But the feeling of having reported only a guess was
not too satisfying. Joe ate gloomily. He didn't pay much attention to
Talley. He had that dogged, uncomfortable feeling a man has when he
knows he doesn't qualify as an expert, but feels that he's hit on
something the experts have missed.

Half an hour after the evening mess--near sunset--a security officer
wearing a uniform hunted up Joe at the airfield.

"Major Holt sent me over to bring you back to the Shed," he said
politely.

"If you don't mind," said Joe with equal politeness, "I'll check that."

He went to the phone booth in the barracks. He got Major Holt on the
wire. And Major Holt hadn't sent anybody to get him.

So Joe stayed in the telephone booth--on orders--while the Major did
some fast telephoning. It was comforting to know he had a pistol in his
pocket, and it was frustrating not to be allowed to try to capture the
fake security officer himself. The idea of murdering Joe had not been
given up, and he'd have liked to take part personally in protecting
himself. But it was much more important for the fake security man to be
captured than for Joe to have the satisfaction of attempting it himself.

As a matter of fact, the fake officer started his getaway the instant
Joe went to check on his orders. The officer knew they'd be found faked.
It had not been practical for him to shoot Joe down where he was. There
were too many people around for this murderer to have a chance at a
getaway.

But he didn't get away, at that. Twenty minutes later, while Joe still
waited fretfully in the phone booth, the phone bell rang and Major Holt
was again on the wire. And this time Joe was instructed to come back to
the Shed. He had exact orders whom to come with, and they had orders
which identified them to Joe.

Some eight miles from the airfield--it was just dusk--Joe came upon a
wrecked car with motorcycle security guards working on it. They stopped
Joe's escort. Joe's phone call had set off an alarm. A plane had spotted
this car tearing away from the airfield, and motorcyclists were guided
in pursuit by the plane. When it wouldn't stop--when the fake Security
officer in