Tom did his best to allay their concern, but finally allowed himself to be hustled up to bed. Dr. Emerson, the Swifts' family physician, was immediately summoned to the house. He pronounced the bruise not serious, but advised that Tom remain quiet, at least for the rest of the day. Bud came to visit the young inventor that evening, just as Sandy was bringing up a tray. On it was a sizzling T-bone steak. "Wow! Wish I could have that kind of service," Bud said jokingly. Then he became serious. "I'd sure like to meet that creep who snagged you, Tom. What a fiendish trick! You realize you might have been killed?" "I realize it, all right," Tom said wryly. The next morning Tom felt no ill effects from his grim adventure and insisted upon driving to Enterprises. He phoned Admiral Walter, whose report was bleak--the searchers had still gleaned no trace of the buried missile. Refusing to be discouraged by the news, or lack of news, Tom went to his private laboratory and applied himself once again to the problem of building an "invisible" submarine. But again success eluded him. At last Tom shook his head in disgust. "May as well get that haircut I started out for yesterday," he decided. Before leaving, Tom phoned Phyl Newton to thank her for the gift of fruit and nuts she had brought over the previous evening after learning of his dangerous experience. They chatted for a while and wound up by making a date for lunch. Tom drove back to town in the family car and got a haircut. Then he picked up Phyl at her home and took her to the yacht club. Here they lunched on the terrace overlooking the sparkling blue waters of Lake Carlopa. The young inventor's spirits were high when he finally returned to his laboratory and buckled down to work. "I'll lick this problem yet," he muttered. "Those enemies of ours are clever, but if they can produce an undetectable sub, there's no reason why I can't do the same." Deep in thought, Tom idly fingered a microphone on his workbench. "In fact," the young inventor mused, "why not go them one better? I'll invent a submarine that's not only invisible to sonar, but equipped to _see them_!" CHAPTER XI SQUARE-DANCE HOAX Random hunches and circuit diagrams flashed through Tom's brain. "The job will boil down to blotting out sonar waves and piercing the enemy's own 'wave-trap defense,'" the young scientist concluded. As Tom struggled with the problem, he lost all track of time. A door swung open and high-heeled boots clumped on the floor tiles. Tom looked up and saw the portly, aproned figure of Chow Winkler entering. "Hi, boss! Can I borrow a radio?" Chow asked. "Kinda like a lil music while I wrassle them pots an' pans in the galley." "Sure, pardner." Tom pointed toward a portable radio on a shelf nearby. Chow's leathery face broke into a grin as he picked it up. "One o' them slick lil transistor doodads, eh?"