“Oh, hello, Mr. Ross,” Eddie said, turning around and standing up. “I didn’t hear you come in.” Teena’s father was a medium-sized man with light-brown hair which was getting somewhat thin on top. He was usually quite cheerful and full of fun, but tonight his face seemed unusually drawn and sober. He stepped to the table, leaned over, and gave both Teena and Mrs. Ross a kiss on the cheek. “Eddie was telling us about atoms,” Teena’s mother said. “Did you know there were three million billion of them in a period?” “How many in a comma?” Mr. Ross said to Eddie, then added quickly, “forget it, Eddie. It wasn’t very funny. I—I’m afraid I don’t feel very funny tonight.” “Sit down, dear,” Mrs. Ross said. “I’ll warm your dinner. You didn’t sound very cheerful when you called to say you would be late. How did everything go at the plant today?” “Not so good,” Teena’s father said tiredly. “In fact, not good at all.” Problems. It seemed that everyone had problems, Eddie thought, as he started to leave. CHAPTER THREE Three days later Eddie learned the nature of the trouble at Acme Aircraft Company. It was midmorning Saturday. Carrying a picnic lunch, he and Teena were hiking along the beach toward the distant U.S. Coast Guard lighthouse which stood on a high point overlooking Moon Bay. Old Captain Daniels, the lightkeeper, had been a friend of theirs for nearly two years. Every once in a while Teena and Eddie went to visit “Cap,” as they fondly called him. Teena would put up a picnic lunch which they shared with the kindly old man whose lonely vigil over the light had warned ships off the rocky coast for a good many years. Eddie wasn’t sure exactly how the conversation got around to Acme Aircraft Company. It seemed that Teena mentioned something about trouble. Eddie asked, “What trouble?” “Didn’t you read the paper this morning?” Teena asked. “We don’t take the morning paper,” Eddie said. “We take the _Globe_.” “The aircraft company has been keeping it quiet,” Teena said, “but somehow the news leaked out. It was all in this morning’s paper.” Actually, Eddie doubted that he would have noticed it, even if they had taken the morning paper. The big thing around his house was the disappearance of the radioisotope. No promising clues had been found. The theft of the isotope remained as much a mystery as it had been from the first day. The few times he had seen his father, he had noticed how much deeper the lines of worry on his face had become. Eddie had avoided asking questions, yet he couldn’t help wondering if his father was in danger of losing his job at the college. Some of the things his mother had said seemed to hint at the possibility. The newspapers had taken a dim view of the robbery. They protested against the carelessness which would enable the theft, in broad daylight, of such a valuable, secret, and hazardous thing as a radioactive isotope.