CHAPTER III
INVISIBLE SUB
Without wasting a moment, Tom lunged through the water toward hisstricken friend. Bud was floundering and thrashing about weakly. Heseemed dazed by the sudden shock of his plight.
"Or maybe the impact of the projectile stunned him!" Tom surmised.
Bud began groping his way upward just as Tom came alongside of him. Tomgrabbed him as best he could, hooking onto his belt. At the same time,the young inventor inhaled deeply, yanked out Bud's useless mouthpiece,and inserted his own in its place.
Bud's eyes glowed with gratitude.
"We'll have to get topside fast," Tom thought, "even though it meansrisking the bends."
He stroked upward and they shot toward the surface. Bud assisted to someextent, partly revived by the gulp of air.
As they rose, fathom by fathom, their progress seemed to growmaddeningly slower. Tom had to let air bubbles escape constantly fromhis mouth. As the pressure decreased, due to the lessening depth of thewater, the air in his lungs expanded and he was forced to breathe out.
Tom noticed with dismay that Bud was not responding very well, hisfeeble strokes were jerky and uncoordinated. "Must've lost pressure toofast when his tank was hit," Tom realized.
The water was growing greener and brighter now as they neared thesunshine. The _Sea Hound_'s shadowy outline loomed just above. With alast desperate burst of strength, Tom lunged upward and they brokewater.
"H-h-help!" Tom gasped.
There was no need for the cry. Hank and his crew, on the seacopter'sforward deck, had already grasped the situation. Strong arms reached outand hauled the two boys aboard.
Both of them were shivering and writhing in pain, only half conscious.
"They have the bends!" Arv Hanson cried in alarm. "Signal the _SkyQueen_ to drop a sling!"
The boys' masks were ripped off. Within moments, Bud had been tightlysecured to the sling, which was reeled back up into the plane. Tomfollowed in a few minutes. Doc Simpson took charge of the patientsimmediately. After a quick examination, he had the boys placed in asmall decompression chamber in the _Sky Queen_'s sick bay.
"How are they?" Hank asked anxiously as he peered through the window ofthe chamber. The medic had given Bud a sedative and he was already fastasleep. Tom remained awake.
"Aside from the pain, not in too bad shape," Doc Simpson replied.
It turned out that Tom's case was not so serious, but Bud had to stay inbed. With Tom, it was only a matter of decompression and he soon was upand about.
Chow, in a chef's cap, with an apron around his paunchy stomach, hadcome stomping in hastily from the galley. "Pore lil ole boys," hefussed. "Brand my snorkel, I never should've let you young'uns go pokin'around down below there without me around to keep an eye on things!"
Tom slapped the loyal old Texan on the back. "If you want a dive, comealong."
"You're goin' back down?" Chow asked.
"In the seacopter," Tom replied. "To find out, if possible, who firedthat projectile at us."
"Then count me in!" Chow declared, stripping off his apron. "I just hopeI get my hands on them sneakin' polecats!"
Slim Davis would pilot the _Sky Queen_ back to Shopton at once, becauseof Bud. Tom and Chow, meanwhile, would join Hank and his crew aboard the_Sea Hound_.
Ten minutes later the sleek seacopter, its searchlight off to avoiddetection, was plummeting downward through water that changed beforetheir eyes from greenish blue to a deep-gray gloom. Iridescent fishdarted past the cabin window.
"Think the enemy sub was searching for our Jupiter prober?" Hank asked.
"It must have been," Tom reasoned.
Hank frowned. "Which means they must have figured out the missile'sposition as fast as our side did."
"And they'll play rough to stop us from finding it," Arv addedforebodingly.
Within moments, the group clustered in the pilot's cabin felt a gentlebump as the _Sea Hound_ settled on the submerged plateau. Tom relaxed atthe controls but kept the rotors going so the craft would remainsubmerged. Meanwhile, the sonarman was probing the surrounding waters.
"Any pings?" Tom asked.
The man shook his head without taking his eyes from the sonarscope."Nothing yet."
Hank Sterling donned a hydrophone headset and listened intently. Thesilence deepened in the _Sea Hound_'s cabin. Suddenly Hank stiffened andthe sonarman cried out:
"A blip, skipper! At two o'clock!"
It was moving rapidly on the scope--something streaking toward theirstarboard beam!
"Good night! It's another missile!" Tom gasped.
He darted back to the controls and gunned the reverse jets just in time!The missile flashed across their bow.
"Great bellowin' longhorns!" Chow gasped weakly. His leathery face hadgone pale under its tan. "The yellow-livered drygulchers!"
"I don't get it," Arv Hanson spoke up. "If they're in firing range, weshould have detected them, shouldn't we?"
Tom nodded grimly. "Whoever our enemies are, they must have perfected away to make themselves invisible to underwater detection.
"_And we'll 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 beasking for trouble."
Slowing the rotors to permit the craft to rise, Tom guided the _SeaHound_ back to the surface. Then he reversed blade pitch for air flightand gunned the atomic turbines. The seacopter rose steeply above thebillowing South Atlantic.
Tom radioed a terse report of their experience to the task-forcecommander and in turn was told that none of the naval craft had eithersighted or picked up any sign of a strange sub.
As they streaked homeward, Chow was still fuming. "Why don't we post adummy 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. Tomcleared with the tower and landed, then went by jeep to baseheadquarters. He called Enterprises and learned that Bud's condition wasimproved, and that Mr. Swift had returned that afternoon. He spoke tohim about the mystery sub.
"This is bad news indeed, son," Mr. Swift said, after hearing how theattacker had defied detection. "You'd better inform Admiral Walter. Hehad 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 jobfirst thing tomorrow."
After hanging up, Tom hopped back to the mainland with Chow in a PigeonSpecial. This sleek little commercial plane was manufactured by theSwift Construction Company in charge of Ned Newton.
Early the next morning Tom and his father drove to Enterprises, and theyoung inventor plunged into the job of organizing an engineering crewfor the missile hunt. Art Wiltessa, a crack underwater specialist aswell as engineer, was placed in charge.
By noon the group had taken off for the South Atlantic in a Swift cargojet. A small portable model of Tom's atomic earth blaster was includedin their equipment. A jetmarine and a diving seacopter were alsodispatched 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 their office.
"Yes. Digging in that silt could be almost as bad as working inquicksand."
Mr. Swift's deep-set blue eyes took on a thoughtful gleam. "Speaking ofsilt, son, I've found the ideal spot for my secret deep-sea farm."
"You mean for growing those plants you use in making Tomasite?" Tomasked.
The elder scientist nodded. Tomasite, a revolutionary plastic which Mr.Swift had developed, possessed amazing insulating properties againstboth heat and radiation. One of its secret ingredients came from c
ertainplants found only in Far Eastern waters. Mr. Swift hoped to transplantthem locally.
"The site is near Fearing Island--about fifty feet in depth," he added.
"You may have a tough time finding gardeners, Dad," Tom pointed out."Men can't work that far down for very long at one time."
"It'll be a problem," Mr. Swift conceded. He finished his coffee, thenlooked up with a twinkle in his eyes. "How about figuring out a solutionfor me, Tom?"
"A new kind of air lung?" Tom was intrigued!