The Spy Paramount by E. Phillips Oppenheim

Fawley brought his Lancia slowly to a standstill at the top of the Sospel Pass. He was surrounded now by the white-capped mountains of the Lesser Alps and, though the day had been warm enough, the evening breeze brought with it a cold tang from the snows. He paused to light a cigarette. The work of mining and tunnelling the mountain range seemed to have progressed even since his last visit. There was a new road cut in the direction of headquarters. Within half a mile of him, around the shoulder of the hill, was the subterranean passage from which he had had so narrow an escape. Yet everywhere there seemed to be a curious stillness. There was no sound anywhere of human life or activities. Underneath his feet, almost underneath the whole range of hills around which the road wound, was another world--an active world bristling with the great vehicles of destruction. From where he sat he could see the ravine down which he had flung himself only a month or so ago. He could recall the sound of the rifle bullets spitting against the rocks, the muttering of the Chasseurs Alpins cursing the darkness. He had escaped where others with as much experience as he had paid with their lives for seeking to learn the secrets of this fortress. Would the luck hold, he wondered.

Tramp! Tramp! Tramp! The sound of men marching close at hand. Fawley, suddenly alert, sat up in his place. They were already making their way around the corner, a little company of weary men with a handful of tired mules. They were almost passing him when the officer who was marching in the middle of the road came to a sudden standstill. He looked incredulously at Fawley. It was the same officer who had found him wandering in the roads and taken him to the Colonel! The meeting was one of mutual amazement. The young lieutenant of the Chasseurs Alpins, however, was this time a very resolute person. He snapped out his orders. In a very few seconds Fawley found himself with a soldier standing on each footboard and another with pointed rifle facing the car.