r. Terrill asked Tom.

"As soon as I can get my craft back to the shop and fit on a new outer
case. That won't take long, as I have some spare ones. But I must help
the Nestors," he went on, speaking to his father. "I didn't mention it
over the wire," he added, "but we've found in the cabin a clew to the
missing man. I must tell Mary and her mother, and help them all I can."

"And allow me to help, too," begged Mr. Terrill. "Since this affects
you, Mr. Swift, and since you are, in a way, working for Uncle Sam, you
must let him help you. This is the first I have heard of the missing
gentleman, of whom your father just told me something, but you must
allow me to help search for him. I will get the United States Secret
Service at work."

"That will be fine!" cried Tom. "I wanted to get their aid, but I
didn't see how I could, as I knew they were too busy with army matters
and tracing seditious alien enemies, to bother with private cases. I'm
sure the Secret Service men can get trace of the persons responsible
for the detention of Mr. Nestor, wherever he is."

"They'll do their best," said Mr. Terrill. "I'm a member of that body,"
he went on, "and I'll give my personal attention to the matter."

Then followed a busy time. Tom did not get to bed until nearly morning.
For he had to arrange to send some of his men to guard the stranded
airship, and then he went to see Mary and her mother, taking them the
good news that the search for Mr. Nestor would be prosecuted with
unprecedented vigor.

"If it isn't too late!" sadly said the missing man's wife.

"Oh, I'm sure it isn't!" declared Tom.

In addition to sending a guard to the airship, other men, some of them
hastily summoned from the nearest federal agency, were sent to keep
watch in the vicinity of the lonely cabin. They had orders to arrest
whoever approached, and a relay of the men was provided, so that watch
could be kept up night and day. Besides this, other men from the Secret
Service began scouring the country around the locality of the cabin,
seeking a trace of the two persons the farmer's son had seen in the
automobile.

"If Mr. Nestor is to be found, they'll find him!" declared Tom Swift.

Mr. Damon, as might be expected, was very much excited and wrought up
over all these happenings.

"Bless my watch chain, Tom Swift!" cried the eccentric man, "but
something is always happening to you. And to think I wasn't along when
this latest happened!"

"Well,