"I wonder now--I wonder what happened to that missing German professor!" and Colonel Tempest suddenly halted, and placed his left hand to his forehead, as some powerful, new idea had arrested his mental faculties.
Then, walking across the room swiftly, he switched on a shaded light which illuminated a large map of Germany, showing the aerial routes, the lines of occupation by the Allies, etc.
"It is just possible," he murmured to himself, "that the two things are connected--the disappearance of this eminent scientist and the appearance of this extraordinary flying machine." Then he switched off the light, and returned to the sheaf of papers and documents on his desk. He sorted out one and placed it on top; it was a decoded message, received some days ago from one of his agents at Constantinople. It ran as follows:--
"Mysterious aeroplane, phantom-like in appearance, passed over here yesterday flying at terrific speed. All our signals disregarded. No navigation lights showing. Our fast scouts gave chase but left hopelessly behind. Came from direction of Adrianople, crossed the Bosphorus, and disappeared rapidly flying south-east. Time shortly after sunset.
AERIAL, CONSTANTINOPLE."
"That is three days ago," continued the Colonel, still thinking aloud, "and here are four similar messages from other sources showing quite plainly the route taken. Great Heavens! if I were not tied to my desk in this place, I would take the fastest scout in the country and chase this infernal night-wizard myself."
A soft tap at the door startled the Commissioner, for during the last three days he had become highly nervous; this affair was getting on his mind, but he recovered himself instantly and called out in a deep voice:--
"Come in!"
The door opened softly and his confidential secretary entered, and announced:--
"Two more cables and a wireless message, sir."