"But suppose there are sentries posted up there?" asked the American, pointing to the farthermost part of the slope.
"Not much! This place is all enclosed with that barbed-wire fence. That's where the sentries are to be found, and that is what is going to give us a lot of trouble."
"And when do we make an attempt to seize a boat?"
"Not while this wind is blowing, thank you. Better to prowl about half-starved in a German fortress than to be lying on the bottom of the North Sea."
"You cautious critter!" ejaculated Detroit.
"Exactly, my dear fellow. Caution is the modern naval officer's sheet anchor. Caution is instilled into him from the moment he's placed in charge of a ship's boat under sail. No doubt it's the means of often neglecting to make full use of an opportunity; but there you are. Modern warfare has no use for fire-eating daredevils; it's the level-headed admiral who will win the next great naval war. It's prosaic, but it's hard facts. Now, easy ahead; it's time to get under way."
Making his way up the vertical iron ladder, Hamerton raised the trapdoor a few inches and listened intently. All was quiet. He emerged from his hiding place, waited until Detroit rejoined him, then carefully replaced the cover on the aperture.
Bearing in mind the experience of the previous night, how without warning the place was flooded with light, the Sub and his companion made their way as stealthily and rapidly as possible to the base of the artificial cliff where the incline merged into the circular basin. Then, keeping close to the wall, they headed towards the upper level.
Suddenly Hamerton came to an abrupt halt and stood with his back hard up against the cliff. Detroit did likewise.
Faintly discernible against the loom of the skyline was a great-coated sentry pacing up and down across the brink of the inclined plane. Barely had he turned to commence another round when a second sentry appeared on the opposite side. Both met approximately in mid-distance, faced about, and retraced their steps.