Sir John let it go at that. He realized that Brian Strong was a man with high motives, and that discussing money matters was distasteful. "I don't care what I get out of the business," declared Brian when uncle and nephew found themselves crossing Trafalgar Square. "They can give me what they like, as long as it's not the Order of the Bad Egg." CHAPTER XXIV War in Home Waters Brian Strong's surmise was a correct one. He had underrated the craftiness of Don Ramon Diaz, Air Minister to the Government of Rioguay. Strong mistrusted Diaz. Diaz mistrusted Strong. Each hoped that the other was unsuspicious. Brian's hasty and daring departure had removed all shadow of doubt on the Rioguayan's part, but that did not give him any great concern. What was more to the point, Ramon Diaz had acquired the secret of Strong's ray apparatus, and had wasted no time in turning it to good account. Sir John Pilrig decided that it was a fortunate circumstance, this interview with a scientist unknown and lacking credentials. Not only had Brian Strong afforded valuable information, but he had unreservedly placed his invention at the Government's disposal. Should the invention come up to expectations--and there was no reason why it should not, judging by the results obtained by the Rioguayan flying-boats on the _Cerro Algarrobo_ engagement--it would reduce the rival aerial forces to a state of stalemate. It was, of course, unfortunate that the secret was in hostile hands, he mused, but there was some satisfaction to be derived from the knowledge that the Rioguayan air forces were not the sole possessors of the mysterious rays. And--a remarkable fact, decided the Deputy Chief of Staff--the inventor had asked nothing, either for himself or his nephew--a rarity in these days of mercenary offers in the name of patriotism. By eleven o'clock on the morning following the momentous interview, Brian Strong, with Peter Corbold as his chief assistant, reported for duty at Whale Island Naval Gunnery Establishment--an artificially-constructed island in the upper reaches of Portsmouth Harbour. Already a large building had been allocated to them as an experimental workshop, complete with lathes, benches, moulds, and drawing-office, with electric light and power, and with a small staff of armourers and electricians--the pick of the highly-skilled naval artificers of the Gunnery School. There, behind closed doors--for no one save the Commodore was allowed entrance--Brian Strong set to work to reconstruct the device that, for all time, it was hoped, was to draw the sting from the terror of the skies. At 4.45 of the same afternoon, a look-out of the R.N. signal station at Culver Cliff in the Isle of Wight heard the rumble of distant gunfire. There was nothing extraordinary in that. Men-of-war carrying out gunnery practice in the Channel, he decided.