The further they carried their investigation the more were these two Englishmen bewildered by what they saw. "Is it possible," gasped Keane, "or am I only dreaming? We have discovered the home of the super-alchemist. After this, nothing will surprise me." "We have discovered the devil’s workshop," replied Sharpe, who did not appear to be half so enraptured as his friend. "Nay, we shall find the philosopher’s stone, or the _elixir vitae_ soon," replied Keane, continuing his investigation. "We are more likely to find the _elixir mortis_ than anything else," said the gloomy one. "This place gives me the shivers. I am sure that I shall have cold feet for the rest of my life." "After this, Hermes and Geber will be dull reading," continued the enthusiast. "Give me the Schwarzwald every time for the real thrill of the alchemist." "Their time might have been more profitably employed, at any rate," remarked Sharpe. "Yes, it is a thousand pities that the wonderful brain which designed and organised all this should have had nothing better in view than brigandage and world revolution." "More misdirected energy," moaned Sharpe; "the greatest brains often make the greatest criminals." "You’re a veritable misanthrope, Sharpe!" said his companion, laughing. "I have reason to be," returned the other. "What do you mean?" "I mean this--we’re not out of the wood yet." "I agree; we’re in the very centre of it," replied Keane. "Yet you did not inflict the _coup de grâce_ on the diabolical vipers, and they will shortly awake. Moreover, the _Scorpion_ may arrive unexpectedly, and we shall be unprepared for her." "What would you do?" "Bring over the machines from Mulhausen, ready to fight this air fiend when he comes." "Ho! So you’re longing for another real air fight, are you, like the ’scraps’ we used to have with the Richthofen ’circus’?" "At any rate, we’d better prepare. Then I’d bind those two criminals hand and foot or surround them with live wires, so that, should they awake unexpectedly, they would not dare to stir." "There is certainly something in what you suggest about bringing the aeroplanes over, though we should have a deuce of a job to land them in this place; they’re by no means possessed of the powers of a helicopter. However, I’ll get into touch with Colonel Tempest and ask for immediate assistance, and also ask him to bring over Professor Verne to investigate these mysterious engineering and chemical appliances." So, leaving the workshop, the live wires and the prisoners to the care of Sharpe, the senior airman devoted all the rest of that morning to investigating the wireless apparatus, examining the secret codes, and trying to get into touch with the Commissioner of Aerial Police. In this, however, he was not very successful, for the air was full of messages, concerning an overdue air-liner which had been expected for some time at Cairo. Perhaps his message had been jammed or lost in the aerial jostle.