Unger was walking straight toward them. Both Bud and Sandy had met him occasionally around town and found him obnoxious. "Sorry, but Morris got tied up," Unger informed them. "He sent me to talk to you." Sandy's blue eyes met Bud's in a flicker of distaste, but she tried to conceal her feelings. "Please sit down," she invited Unger politely. "What square-dance numbers does Mr. Morris do?" Len Unger shrugged. "You name 'em." "But, my goodness," Sandy said, puzzled, "how do we know he'll have the squares I name?" Unger stared at her as if he did not quite understand. "You mean, can he call off the dances you want? If he can't, I'll let you know." "Does he do patter calls or singing calls?" Bud put in. Again Unger hesitated, then said, "Both." "Wonderful!" Sandy exclaimed gleefully. "I thought he only did singing calls." After a moment's thought, she went on, "Well, let's see. What about 'Birdie in the Cage'?... And 'The Gal from Arkansas' ... 'Uptown and Downtown'...." Unger jotted the names on the back of an envelope. Pausing a moment, he remarked, "Guess your brother was too busy to make it today, eh, Miss Swift? What kind of ex-spearmints is he working on now?" "I really couldn't say," Sandy replied coldly. She always made it a point not to discuss Tom Jr.'s or her father's research work with outsiders. Unger persisted chattily, "I read where he handled that Jupiter probe shoot for the Navy." "Let's get back to square dancing," snapped Bud. As he and Sandy finished planning the program, Len Unger continued to drop remarks and questions about "The Great Tom Swift" and his inventions. All prying queries were side-stepped. As soon as possible Sandy and Bud cut short the conversation and left the yacht club. Unger's face wore an angry sneer as they walked out. "What a creep!" Bud said, when he and Sandy were driving back in his red convertible. Meanwhile, in his private laboratory at Enterprises, Tom was somewhat discouraged. He had tried several different experimental attacks on the problem of an undetectable submarine. None had worked out successfully. "I thought that idea of a sonar-wave baffle might lead somewhere," he murmured, "but it looks as though I'm wrong." Flopping down on a stool at his workbench, Tom cupped his chin in his hands. He was frowning, deep in thought, as the pudgy figure of Chow Winkler came into the laboratory. "'Smatter, boss?" the cook inquired cheerfully. "Ain't your ole think box workin' today?" "Doesn't seem to be," Tom confessed. "Give it time, son. Tomorrow's another day," Chow said philosophically. "What you need is a haircut for the square dance." Tom laughed in spite of himself. "Maybe you're right, Chow. Might help me think better." Tom got off the stool and stretched out the kinks in his legs. He strolled outside with Chow, then scootered to the parking lot and hopped into his sleek, silver sports car.