"We're wasting our time," Thurston said finally, with a look of disgust. "But I made a promise in the name of the United States government and the promise will be kept." Turning to Chief Slater, the CIA man added, "Turn him over to the FBI and have them take him to New York. I'll arrange for a seat on the first plane for Brungaria." Tom drove back thoughtfully to Enterprises. Bud was waiting in his laboratory with news. "Your dad went from Washington to Fearing Island and has gone up to your space outpost," Bud reported. "He has to do some experiments for the government project he's working on." The outpost was a space station which Tom Swift Jr. had built 22,300 miles above the earth. It was a production factory for his famous solar batteries, and also an immensely valuable setup for space research and exploration. "Think I'll radio Dad and let him know what's going on," Tom decided. "He may have some good suggestions. He usually does!" Tom warmed up his private transmitter-receiver and beamed out a code call through the automatic scrambler. Seconds later, the loud-speaker crackled in response. But just as the outpost operator's voice came through, the radio set exploded in Tom's face! CHAPTER IX THE CAVE MONSTER "Skipper!" Bud cried anxiously as Tom staggered back, his hands to his face. "I'm all right--no harm done," Tom assured his friend. Both boys were a bit shaken by the accident, nevertheless. Chow came rushing in as Bud was brushing the fragments of debris from Tom's clothes and examining the young inventor's face. "Brand my flyin' flapjacks, what happened?" Chow asked. The chef had been bringing a tray of fruit juice to the laboratory and had heard the explosion outside. "The radio set just blew up in my face," Tom explained. "Fortunately, the equipment was transistorized mostly with printed circuits. Otherwise," he added, "I might have been badly cut by slivers of glass from the exploding vacuum tubes." As it was, the young inventor had suffered only a few slight scratches and a bruise on the temple from a piece of the shattered housing. Bud swabbed Tom's injuries with antiseptic from the first-aid cabinet while Chow poured out glasses of grape juice. "What caused it, Tom?" Bud asked as they paused to sip the fruit drink. "Good question," Tom replied. "Frankly, I don't know." But he was wondering if the set might have been sabotaged. Tom was still eager to get in touch with his father and telephoned the electronics department to bring another set to his laboratory. Chow left just as the new set arrived. Tom hooked it up quickly, donned a set of goggles, and tuned to the space-station frequency. Then he picked up the microphone and stepped well back from the set, waving Bud out of range at the same time. "Tom Swift calling Outpost!... Come in, please!" A moment later came another explosion! _The new set had also blown up!_