Tom had ordered the space oscilloscopes to be manned constantly, both at Fearing and at Enterprises, in case of a flash from Exman. But no word had yet been received when Tom and his companions arrived at the mainland late that afternoon. Mr. Swift greeted his son warmly at the airfield. Tom had refrained from radioing the news to Enterprises after the hijacking and the missile attempt. Any such message, Tom feared, might be picked up by the enemy and bring on another attack. But the young inventor had telephoned his father immediately after calling Washington. Now Mr. Swift threw his arm affectionately around the lanky youth. "You look pretty well bushed, son. Why not hustle home and call it a day? That goes for the rest of you, too," he added to Bud, Chow, and the others. "You've just risked your lives and the strain is bound to tell." Tom urged his companions to comply. "But I'm sticking right here," the young inventor told his father. "I want to be on hand the minute Exman contacts us." Bud insisted upon staying with his pal. The two boys ate a quiet supper in Tom's private laboratory and finally lay down on cots in the adjoining apartment. But first Tom posted a night operator to watch the electronic brain. "Wake me up the second that alarm bell goes off," he ordered. "Okay, skipper," the radioman promised. No message arrived to disturb the boys' rest. Tom felt a pang of worry as he dressed the next morning, and then relieved the man on duty at the decoder. Had the Brungarians somehow outwitted him? Surely Exman should have reported by this time! "Relax, pal," Bud urged. "Our space chum's hardly had time to learn any secrets yet. Besides, those Brungarian scientists are probably giving him the once-over with all sorts of electronic doodads. Why risk sending a message till he has something important to tell us?" "That's true," Tom admitted. Chow brought in breakfast. "You jest tie into these vittles, boss, an' stop frettin'," the cook said soothingly. "I reckon Ole Think Box won't let us down." Tom sniffed the appetizing aroma of flapjacks and sausages. "Guess you're right, Chow," he said with a chuckle. As the boys ate hungrily, Tom's thoughts turned back to the problem of how to equip Exman with senses. He talked the project over with Bud. Most of his ideas were too technical for Bud to follow, but he listened attentively. He knew the young inventor found it helpful to have a "sounding board" for his ideas. "Too bad I didn't have time to tackle the job before Exman was kidnaped," Tom mused. "Think how much more he could learn with 'eyes' and 'ears'!" "Stop crabbing," Bud joked. "Isn't an electronic spy with a brain like Einstein's good enough?"