have to do the same!_" he vowed inwardly. Aloud, Tom said,
"I hate to run from those sneaks, but if we stick around, we'll be
asking for trouble."

Slowing the rotors to permit the craft to rise, Tom guided the _Sea
Hound_ back to the surface. Then he reversed blade pitch for air flight
and gunned the atomic turbines. The seacopter rose steeply above the
billowing South Atlantic.

Tom radioed a terse report of their experience to the task-force
commander and in turn was told that none of the naval craft had either
sighted or picked up any sign of a strange sub.

As they streaked homeward, Chow was still fuming. "Why don't we post a
dummy sub there to scare off the varmints?"

"I'll pass the idea along to the Navy," Tom said with a grin.

Night had fallen when the searchers arrived back at Fearing Island. Tom
cleared with the tower and landed, then went by jeep to base
headquarters. He called Enterprises and learned that Bud's condition was
improved, and that Mr. Swift had returned that afternoon. He spoke to
him about the mystery sub.

"This is bad news indeed, son," Mr. Swift said, after hearing how the
attacker had defied detection. "You'd better inform Admiral Walter. He
had to fly back to Washington."

"I'll call him right away," Tom promised.

The admiral was equally disturbed when Tom succeeded in reaching him.
"We must find that missile as soon as possible--at any cost," he said.
"Tom, you Swifts have had considerable experience in undersea dredging.
Could you send a team of engineers to assist us in the work?"

"Yes, sir," the young inventor replied. "I'll assign men to the job
first thing tomorrow."

After hanging up, Tom hopped back to the mainland with Chow in a Pigeon
Special. This sleek little commercial plane was manufactured by the
Swift Construction Company in charge of Ned Newton.

Early the next morning Tom and his father drove to Enterprises, and the
young inventor plunged into the job of organizing an engineering crew
for the missile hunt. Art Wiltessa, a crack underwater specialist as
well as engineer, was placed in charge.

By noon the group had taken off for the South Atlantic in a Swift cargo
jet. A small portable model of Tom's atomic earth blaster was included
in their equipment. A jetmarine and a diving seacopter were also
dispatched from Fearing to assist in the operations.

"It's apt to be a long-drawn-out job--and dangerous," commented Mr.
Swift as he lunched with Tom in th