Suddenly they were awakened by the dull buzz of an aerial propeller. Crawling from their place of repose, Dick and the midshipman saw a French monoplane flying barely two hundred feet above the ground.
"We'll try and attract that fellow's attention," exclaimed Dick. "I don't suppose he can give us a lift, but he may be able to----"
There was no time to complete the sentence. Dashing out in the open, the Sub waved his arms, shouting at the top of his voice:
Overhead swept the aeroplane. The observer leant over the chassis and critically surveyed the two figures in German uniforms. He shouted something, but the words were unintelligible, although he could distinctly hear the Sub's call for aid.
"Nous sommes prisonniers Anglais--prisonniers échappés!" bawled Dick frantically.
The Frenchman again waved his hand. The monoplane calmly continued its course, then, majestically circling, it began to descend.
"Hurrah!" shouted the midshipman. "Who says the age of miracles has passed?"
Even as he spoke an irregular volley burst from a slight depression in the ground about five hundred yards from where the officers stood. Sharply banking, the aeroplane rose to a safe distance, dropping a bomb as she did so, then began to retrace its course.
"Look out!" exclaimed Dick warningly, as the monoplane passed nearly overhead.
Almost at the first report of the rifles the fugitives withdrew from their exposed position. They were now in danger from another direction, as Dick had foreseen.
A small black object dropped from underneath the chassis of the aeroplane. Rapidly gathering speed it fell within twenty yards of the Sub and his companion. It was a bomb; but owing either to faulty mechanism or to the fact that it alighted on soft sand, it failed to explode, otherwise the officers would have been blown to pieces.
"What luck!" muttered Farnworth. "I suppose those fellows took us for a pair of treacherous German skunks. It wasn't their fault."
"Anyhow, I'm not going to wait till those chaps come up to investigate," added Dick, referring to the still invisible riflemen. "So here's off! Keep to the dip in the ground and avoid the sand. We don't want to leave our tracks."
Breaking into a steady run the fugitives hurried away from the direction of the interrupters of their peace of mind. Already the monoplane was a mere speck in the distance.