"Morning! So this is where you young cubs spend your holidays, while the whole world is ramping at me for not catching this infernal brigand. What have you got to say for yourselves?" Keane was not at all put out by this dour greeting; he knew his chief too well, and admired him accordingly. Merit is not always accompanied by a bland and urbane countenance, neither do brains always accompany a white shirt front. "I have that to say which will almost make you jump out of your skin, sir," replied Keane, "but we must somehow get these aeroplanes under cover, or properly camouflaged, for the _Scorpion_ may arrive any minute." "Eh? What’s that you say, boy?" exclaimed Tempest, leaping from the fuselage. "The _Scorpion_?" "Yes, sir." "Why, that is the name of your infernal raider, isn’t it, Captain Watson?" and here the colonel turned and addressed his passenger, who was none other than the skipper of the air-liner which had been so roughly handled in the Hamadian Desert. "The same, sir." "And the professor, Keane? I sent you to track the professor. Have you found him?" "He is our prisoner, Colonel," and Keane bowed stiffly, and pointed to the half-hidden hangar, where the two prisoners, who were now partly roused, had been safely secured. An exclamation of pleasure and surprise broke from this dour-looking man when he heard this news, and his face became wreathed with smiles as he advanced to both Keane and Sharpe, shook them warmly by the hand, and said:-- "Thank you, my boys; I knew if it could be done you would do it, though I could ill spare you for the job. Yesterday my reputation was in shreds; I am to be charged with inefficiency, and a public enquiry is to be held. But you two wolf cubs have re-established my character; I can never thank you enough. Now lead on, show us this evil-minded genius! Professor Verne here, who has come in the second Bristol, with Captain Hooper, is anxious to see him. He may redeem him yet from the error of his ways, and it is vital that this secret of his should be in other and better hands, else it will always be a danger to the public." So, whilst the party were conducted indoors, and shown the marvels of the modern house of alchemy, the two professors were introduced, and began a series of disputations, very embittered at first, as the German, though relieved of his bonds, and made as comfortable as the circumstances would permit, resolutely refused to give any particulars of his discovery, or even to display the slightest amiability towards his distinguished visitor, though they were not unknown to each other, and had even studied at Heidelberg together in their younger days.