way. All the outgoing night shift and some of the incoming day
shift have been held under suspicion, until they can be examined and
carefully questioned. I heard your Chief of Police--whom I know and
knows me--assert that without doubt the bomb had been placed by one of
the workmen. I wonder what makes him think that. Also the police are
hunting for everyone seen loitering about the airplane plant during the
past twenty-four hours. They'll spend days--perhaps weeks--in
investigating, and then the affair will quiet down and be forgotten."

"You fear they will not be able to apprehend the criminal?" from the
colonel.

"Not the way the police are going at it. They're virtually informing
the criminal that they're hunting for him but don't know where to find
him, and that if he isn't careful they'll get him. So he's going to be
careful. It is possible, of course, that the fellow has left traces--
clues that will lead to his discovery and arrest. Still, I'm not
banking much on that. Such explosions have been occurring for months,
in various parts of the country, and the offenders have frequently
escaped. The government suspects that German spies are responsible, but
an indefinite suspicion is often as far as it gets. Evidence is
lacking."

"How about your boasted department of justice, and the secret service?"
asked Mary Louise.

"They're as good as the German spy system, and sometimes a bit better.
Don't think for a minute that our enemies are not clever," said Josie
earnestly. "Sometimes our agents make a grab; sometimes the German spy
remains undiscovered. It's diamond cut diamond--fifty-fifty. But when
we get every alien enemy sequestered in zones removed from all
factories doing government work, we're going to have less trouble. A
lot of these Germans and Austrians are liberty-loving Americans, loyal
and true, but we must round up the innocent many, in order to squelch
the guilty few."

The following week was one of tense excitement for Dorfield. Federal
officers poured into the city to assist in the investigation; the
victims were buried with honor and ceremony, wrapped in American flags
to show that these "soldiers of industry" had been slain by their
country's foe; the courtrooms were filled with eager mobs hoping that
evidence would be secured against some one of the many suspects.
Gradually, however, the interest decreased, as Josie had predicted it
would. A half dozen suspects were held for further examinati