"They obtained the guarantee." "I remember," said Mr. Llewellyn John, "it was stolen." "Mr. Dene used to leave his safe open with such papers in it as he wanted the enemy to see. That's what he meant when on one occasion he said, 'If you've got a hungry dog feed it.'" Sir Bridgman North laughed, Sir Lyster turned to him reproachfully. "Mr. Dene became convinced that an effort would be made to kidnap and hold him to ransom, the price being the plans of the _Destroyer_. Department Z. also became convinced of this, but at a later date. As a precaution John Dene sent to England by another ship his twin brother, known as James Grant. When everything was ready the two changed places; that accounted for the strangeness of manner that Miss West noticed with Mr. Dene a few days before his disappearance." Malcolm Sage then went on to explain the method by which the false John Dene had been kidnapped, and of Department Z.'s discovery with relation to Mr. Montagu Naylor. "But all that time what happened to the _Destroyer_?" "The _Destroyer_ was responsible for the extraordinary increase in the mortality among U-boats." Mr. Llewellyn John jumped from his chair as if he had been thrown up by a hidden spring. "But--but----" he began. "Mr. Dene hit upon a clever ruse," continued Sage, "and----" "But the advertisements! Did you know this at the time?" "It was known at Department Z., sir, and the advertisements were to convince the Hun of our eagerness to find John Dene so that we might start operations." "I see, I see," cried Mr. Llewellyn John; "but how on earth did you ferret all this out?" "We just sat down, sir, and waited for the other side to make mistakes," said Malcolm Sage quietly, "just as the Opposition does in the House of Commons," he added slyly. And Mr. Llewellyn John smiled. "It was better to say nothing about the Finlay business," said Malcolm Sage, as he and Colonel Walton walked back to St. James's Square. "It's results they're concerned with." Colonel Walton nodded. "We must see John Dene, however," he said. "If only for the good of his own soul," said Sage, as he knocked his pipe against a railing. CHAPTER XIX COMMANDER JOHN DENE GOES TO BOURNEMOUTH I Late one afternoon when Dorothy and Mrs. West were walking along the Christchurch Road on their way back to the boarding-house for dinner, Dorothy suddenly gave vent to an exclamation, and with both hands clutched her mother's arm so fiercely that she winced with the pain. "Look, mother," she cried, "it's----" Following the direction of her daughter's eyes Mrs. West saw walking sturdily towards them on the other side of the road, a man in the uniform of a naval commander. In his mouth was a cigar, from which he was puffing volumes of smoke. With a little cry Mrs. West recognised him. It was John Dene of Toronto. There was no mistaking that truculent, aggressive air of a man who knows his own mind, and is determined that every one else shall know it too.