CHAPTER XV

  MOUNTAIN HIKE

  "After adequate doses of your space vitamin, Dad, a skin diver couldtackle almost any undersea job in my hydrolung!" Tom exclaimed. "Hewouldn't be subjected to any antiosmosis troubles with his bodytissues."

  His father nodded. "For the first time, man might become a _truly marinecreature_!"

  "Wow! Think of it!" Bud gasped excitedly. "With Tom's hydrolung and aknife to hunt his own food, he could practically live in the sea!"

  "That's no farfetched dream, Bud." Tom's steel-blue eyes flashed at thethought of new fields of scientific conquest. "This discovery of Dad'sand Doc Simpson's opens up some really amazing possibilities."

  Most important at the moment, the vitamin would be a great boon incarrying out search and digging operations for the Jupiter prober. Withfresh enthusiasm, Tom returned to his laboratory to work on the newsonar gear. In his own mind, he had already named it a "quality analyzersonar," since that exactly described the way it would function.

  "Hmm, let's see," Tom mused as he settled down at his workbench, pencilin hand. "Besides a regular sonarscope, I'll need at least three unitsfor the gear."

  First, he would need an oscillator to produce the complex pulse. Next,of course, an oscilloscope to check the pulse as it was beamed out.Last--but highly important--a correlation calculator.

  This latter unit would compare the original pulse with the returningechoes. If an echo had a high enough "standard of acceptance"--that is,if its quality was very near the original pulse, it would show up on thescreen in the normal way. If the echo came back blurred, or if "shadowechoes" showed up, these would be separated and appear on the screencolored red.

  "Whew!" Tom sighed as he realized the complicated job of circuit designthat lay ahead. "This sure is going to burn some midnight oil!"

  The young inventor worked all afternoon at a furious pace, breaking offtoward dinnertime to telephone his mother that he would be stayingovernight at the lab. After a hasty meal, he resumed his layout job atthe drawing board and by midnight had finished designing his qualityanalyzer sonar.

  Whipping off his eyeshade, Tom went into the apartment next door andstretched out to snatch a few hours' sleep. But as usual when in themidst of an exciting new project, he was too keyed up to rest for long.

  Before daylight, Tom was back at his workbench ready to begin assemblingthe units of his new sonar gear. Later he phoned Chow but scarcelypaused to eat when the cook arrived with his order.

  "Brand my solar stovepipe!" Chow scolded. "Take time to eat your vittlesproperly, boss!"

  "Hmm?... Oh, sure." Tom looked up and grinned.

  The stout old Texan stomped out, shaking his head.

  As the morning wore on, the pace at which Tom had been working began totell on the young inventor. His head nodded again and again. Graduallyhe fell forward into an exhausted doze.

  The next thing Tom knew, he was sailing through the air, high aboveSwift Enterprises. Lake Carlopa was a tiny blue puddle below, and thetown of Shopton a mere cluster of toy buildings in the distance.

  "Good grief!" Tom exclaimed with a gulp. "What's keeping me up?"

  He was floating freely, without the support of any aircraft--or even oneof his amazing force-ray repelatrons!

  The discovery triggered off disaster. Like a character in a moviecartoon, now that he knew he had nothing to support him, Tom instantlywent plunging downward--down, down, straight into the lake!

  _Splash!_

  Tom gasped and shuddered and shook his head like a drenched terrier.

  _Another splash!_ As Tom brought his eyes into focus, he realized he wasback at his workbench in the laboratory. Chow was standing in front ofhim, holding a half-empty pail of water, ready to splash him again!

  "Hey! Cut it out!" Tom cried out, jerking bolt upright. Then, as he sawthe disturbed look on Chow's face, Tom burst out laughing. "Okay. Relax,old-timer! Guess I was dreaming."

  "Brand my snake oil!" Chow said. "You looked so pale an' pasty, you hadme plumb scared, Tom! I couldn't wake you nohow!" Worriedly the cookadded, "What you need is a good beefsteak and some sunshine. You beenunder water too long."

  "In more ways than one!" Tom chuckled as he grabbed a towel and driedhimself off.

  The beefsteak, with crisp golden-brown French fried potatoes, wasalready at hand on Chow's lunch cart. Tom ate with a hearty appetiteand the stout chef went off, secretly plotting to arrange the secondhalf of his prescription.

  When he reached the galley, Chow plucked the wall phone off its hook andcalled Bud at an airfield hangar. After a brisk conversation, he hungup, grinning contentedly.

  At one o'clock Bud came bursting into Tom's laboratory. "Snap to,skipper!" he announced. "You have company!"

  Tom looked up from his work in surprise.

  "_Ta-daaa!_" Bud sang out, imitating a trumpet flourish.

  Sandy and Phyl Newton marched in, smiling.

  "Boy, this _is_ a surprise!" Tom got up to greet them. "A mightypleasant one. But what's the occasion?"

  "The occasion is that you're coming on a mountain hike with us, out inthe nice fresh air and sunshine!" Sandy informed him.

  "And please don't argue," Phyl said with a giggle. "It's for your owngood--not to mention ours."

  "I suppose Chow Winkler put you up to this." Tom grinned.

  "Never mind that," Sandy said sternly. "Just come along quietly. It's abeautiful day."

  Tom glanced at his workbench cluttered with drawings and electronicgear. "Well, okay, since you're twisting my arm," he agreed. "I guess itmight clear my brain at that."

  "Now you're talking." Bud clapped Tom on the back and propelled himtoward the two girls, who promptly seized his arms before he mightchange his mind.

  On their way to the door, however, the telephone rang. Tom insisted uponanswering it, in spite of the girls' scolding.

  "Tom Swift Jr. talking."

  "This is Chief Slater, Tom," said the voice at the other end of theline. "Dimitri Mirov wants to see you. I don't know what's up, but hemight be ready to tell something worth while. Could you drop by?"

  "Sure thing, Chief. Right away!" Tom hung up, excited by the thoughtthat the Brungarian might be about to reveal an important secret. "Mindstopping by police headquarters first?" he asked his friends.

  Minutes later, Bud's red convertible pulled up in front of the graystone building. Tom jumped out and dashed up the granite steps.

  "I've had Mirov transferred to a cell by himself," Chief Slater said ashe took Tom back to see him. "Figured he might talk more freely awayfrom his pals."

  The prisoner, however, showed no eagerness to do so at Tom's arrival. Heremained slouched on his bunk as the young inventor pulled a chair up tothe cell bars. His only response was a slight curl of the lips.

  "Have you heard about my country's new submarine?" Mirov inquired afterChief Slater left.

  Tom nodded curtly.

  "When are _you_ going to build one?" Mirov prodded slyly.

  "Look!" Tom snapped. "You asked to see me. Here I am. What is it youwant?"

  Mirov shrugged with a look of amusement. "To make a bargain with you,"he replied casually. "I know the secret of that sub. Get me and myfriends released and I'll give it to you."

  Tom had no intention of doing so, but he parried the offer, hoping todraw Mirov out further. The prisoner, however, would say nothing more.

  At last Tom gave up and rose to leave. "I'll think over yourproposition," he said.

  He heard Mirov chuckle as he walked away. Somewhat puzzled, Tom reportedthe conversation to Chief Slater and also telephoned the plant to informAmes.

  Then he hurried back to the car. Bud frowned upon hearing Tom's story.

  "Do you think he's on the level?"

  Tom shrugged as they headed out into the countryside. "I may be wrong,but the whole thing sounded fishy."

  "Now look!" Sandy said severely. "If we're going to enjoy this hike,we're _not_ going to talk about Brungarians or inventions or th
at lostmissile. From now on, it will cost anyone five cents every time hebreaks the rule!"

  The boys chuckled and agreed. But agreeing proved easier than keepingthe rule. Again and again, either Tom or Bud would inadvertently drop aremark about their submarine experiments or the search in the SouthAtlantic. By the time they had parked in the hills and started climbing,Sandy's and Phyl's pockets were jingling with coins.

  "What are you going to do with it all?" Bud asked jokingly.

  "_Give it to us!_" snapped a strange voice.

  As the four young people turned with a start, they saw two men burstfrom the shrubbery just behind them.

  Both were holding guns!