ind out where I am. I'll drop back here in a
week."

There were instruments to be installed, and Chet would look after
that. He would test the motors where the continuous explosion of
super-detonite would furnish the terrific force for their driving
power. Then the exhaust from each port must be measured and thrusts
equalized, where needed, by adjustment of great valves. All this Chet
would finish. And then--a test flight. Harkness hoped to be back for
the first try-out of the new ship.

"I'll be seeing you in a week," he repeated. "You'll be that long
getting her tuned up."

But Chet Bullard grinned derisively. "Two days!" he replied. "You'll
have to step some if you get in on the trial flight. But don't worry;
I won't take off for the Dark Moon. I'll just go up and play around
above the liner lanes and see how the old girl stunts."

Harkness nodded. "Watch for patrol ships," he warned. "There's no
traffic directly over here--that's one reason why I chose this
spot--but don't let anyone get too close. Our patents have not been
applied for."

* * * * *

Harkness spent a day in New York. Then a night trip by Highline
Express took him to London where he busied himself for some hours.
Next, a fast passenger plane for Vienna.

In other days Walter Harkness would have chartered a private ship to
cut off a few precious hours, but he was traveling more economically
now. And the representatives of his foreign competitors were not now
coming to see him; he must go to them.

At the great terminal in Vienna a man approached him. "Herr Harkness?"
he inquired, and saluted stiffly.

He was not in uniform. He was not of the Allied Patrol nor of any
branch of the police force that encircled the world in its operations.
Yet his military bearing was unmistakable. To Harkness it was
reminiscent of old pictures of Prussian days--those curious pictures
revived at times for the amusement of those who turned to their
television sets for entertainment. He had to repress a smile as he
followed where the other led him to a gray speedster in a distant
corner of the open concourse.

He stepped within a luxurious cabin and would have gone on into the
little control room, but his guide checked him. Harkness was mildly
curious as to their course--Schwartzmann was to have seen him in
Vienna--but the way to the instrument board was barred. Another
precise salute, and he was motioned to the cabin at the rear.