"Too steady for rifle-firing," suggested the mate. "Looks to me like a bush fire."
"By Jove, I hope not," said the sub earnestly. "The grass will catch like tinder."
A minute or so passed, then Denbigh lowered his binoculars.
"You're right, Armstrong," he said. "It is a fire. Those brutes have set the grass ablaze to cover their retreat."
"Hark!" exclaimed the mate.
Overhead came the unmistakable buzzing of an aerial propeller. One of the sea-planes, if not both, was returning.
Seizing a flashing-lamp Denbigh directed it skywards. It was the only means at his disposal for communication.
"All right?" he asked.
A light blinked through the darkness.
"Dash, dot. Pause. Dash, dash, dash" it flashed; then it ceased abruptly. Nevertheless the answer was to the point. It was NO.