In short, jerky sentences John Dene outlined his scheme of operations, the others listening intently. From time to time Sir Bridgman or Admiral Heyworth would interpolate a question upon some technical point, which was promptly and satisfactorily answered. John Dene seemed to have forgotten nothing. For two hours the four sat discussing plans for a campaign that was once and for all to put an end to Germany's submarine hopes. During those two hours the three Englishmen learned something of the man with whom they had to deal. Sir Bridgman's tact, cheery personality and understanding of how to handle men did much to improve the atmosphere, and gradually John Dene's irritation disappeared. It was nearly three o'clock before all the arrangements were completed. John Dene was to receive a temporary commission as commander as soon as the King's signature could be obtained. The _Destroyer_ was entered on the Navy List as H4, thus taking the place of a submarine that was "missing." John Dene had stipulated that she should be rated in some existing class, so that the secret of her existence might be preserved. In short, sharp sentences he had presented his demands, they were nothing less, and the others had acquiesced. By now they were all convinced that he was right, and that the greatest chance of success lay in "giving him his head," as Sir Bridgman North expressed it in a whisper to Sir Lyster. A base was to be selected on some island in the North of Scotland, and fitted with wireless with aerials a hundred and fifty feet high, "to pick up all that's going," explained John Dene, conscious of the surprise of his hearers at a request for such a long-range plant. Here the _Destroyer_ was to be based, and stores and fuel sufficient for six months accumulated. This was to be proceeded with at once. "I shall want charts of the minefields," he said, "and full particulars as to patrol flotillas and the like." Admiral Heyworth nodded comprehendingly. "By the way," he said, "there's one thing I do not quite understand." "Put a name to it," said John Dene tersely. "How do you propose to keep at sea for any length of time without recharging your batteries?" "We shall be lying doggo most of the time," was the reply. "Then in all probability the U-boats will pass over you." "We shan't be lying at the bottom of the sea, either," said John Dene. "What!" exclaimed Admiral Heyworth, "but if your motor's cut off, you'll sink to the bed of the sea--the law of gravity." "The _Destroyer_ is fitted with buoyancy chambers, and she can generate a gas that will hold her suspended at any depth," he explained. "This gas can be liquefied in a few seconds. Her microphone will tell her when the U-boats are about; it's my own invention." Sir Lyster looked from one to the other, unable to grasp such technicalities; but conscious that Admiral Heyworth seemed surprised at what he heard.