you can be in at the finish," promised Tom, and it was strange
how his promise was fulfilled.

Meanwhile there was much to do. During the time the Secret Service men
were busy looking up clews which might lead to the finding of Mr.
Nestor and keeping watch in the vicinity of the hut, Tom had his
airship brought back to the hangar, and a new silencer was attached.
While this work was going on the place was guarded night and day by
responsible men, so there was no chance for an enemy spy to get in and
do further damage.

An investigation was made of the Universal Flying Machine Company, but
nothing could be proved to link them with the outrage. Gale and Ware
were in Europe--ostensibly on government business, but it was said that
if anything could be proved connecting them with the attempt made on
Tom Swift's craft, they would be deprived of all official contracts and
punished.

All this took time, and the waits were wearisome, particularly in the
case of Mr. Nestor. No further trace of him was found, though every
effort was made. Tom began to feel that his boast of his enemies having
to get up early in the morning to get ahead of him, had been premature,
to say the least.

Tom Swift worked hard on his new Air Scout. He determined there would
be nothing lacking when it came to the government test, and not only
did he make sure that no enemy could tamper with his machine, but he
took pains to see that no inherent defect would mar the test.

Jackson and the other men helped to the best of their ability, and Mr.
Swift suggested some improvements which were incorporated in the new
machine.

One of the puzzles the Secret Service men had to solve was that of the
connection, if any, between the men who had to do with the missing Mr.
Nestor and those who had damaged Tom's airship by filing the muffler
case so it was weakened and burst. That there was some connection Tom
was certain, but he could not work it out, nor, so far, had the
government men.

At last the day came when the big government test was to be made. Tom
had completed his Air Scout and had refined it to a point where even
his critical judgment was satisfied. All that remained now was to give
Mr. Terrill a chance to see how silently the big craft could fly, and
to this end a flight was arranged.

Tom had put the silencer on a larger machine than the one he and
Jackson had used. It held three easily, and, on a pinch, four could be
carried. Tom's plan was to