"Now, all hands set to work to watch for a flare," Andrew commanded. "We'll divide the city into various portions, and so make sure by giving a different part to each one of us that the Major's signal cannot go undetected."
But though the eyes turned upon the dark surroundings of the beleaguered city never left their object, there was no flare to attract their attention, and presently the first signs of dawn warned Andrew and his comrades that the time had come to depart. A loud detonation in the far distance, and a streaming flame of fire, hastened their decision, and they rose at once and headed away from the city followed by the noise of artillery in action. In fact, a fierce attack had begun upon Adrianople, and though the huge airship put many miles between her and the contending armies, the dull muffled roar of guns still reached them on occasion. But towards evening the battle slackened, and that night, when once more over the city, there was not a sound to disturb the silence; not a note came to the ears of the listeners above to tell them of the armies beneath them.
"Fine and clear, but dark enough for our purpose," said Joe, straining his head over the rail of the observation platform of the vessel. "Let us hope that we shall see the signal this evening, for I confess that I shall be glad to get away from those guns. Did you see the shells bursting as we left in the morning?"
"Guess I did," came Andrew's emphatic answer. "And a nice little mess they'd make of this ship if one hit us."
"Or came within a hundred yards of hitting us," said Joe decidedly. "If a shell were to burst within easy distance, the chances are that the concussion would break the framework and cause the gas to explode. So let's hope we shan't be long in such an unpleasant neighbourhood."
But the night passed again without so much as a flicker from the city. Major Harvey made no sign of his presence. Was he captured, or shot? or had he merely failed to discover Charlie?
"Captured or shot," said Andrew promptly, when they began to discuss the matter. "If he had merely failed to discover his friend he would have sent us a signal, and on returning to us would have made other plans to recover this information. There is no signal. That means that the Major cannot make it. In fact, he is dead, or he is a prisoner."
"While we are left helpless above the city," Joe added. "What's to be done? We'd never think of leaving the place till we are quite sure what has happened."
"Never," declared Andrew with energy. "Besides, there's another important matter to consider and to keep us here. The Major distinctly told us that Charlie possessed information of vital importance to the British Government. Then we have two reasons for remaining, one being the safety of our friend the Major, and the other being the need to discover Charlie. That seems to me to present unheard-of difficulties. For Charlie is merely a name. We haven't even a description of this officer incarcerated in Adrianople. Come, Commander, help us. This is a real difficulty."
It was more than that. It was a dilemma, for how could Andrew and Joe and his friends help the Major, seeing that they were high in the air? And how could they discover a man in the city of Adrianople of whose appearance they had no knowledge?