“Maybe Joan’ll need it, anyway,” he said, and thrust it in his pocket. “We must——Say, git busy! Look!”

Buck’s quick eyes had suddenly caught sight of a fresh disturbance in the water. Of a sudden the whole surface of the lake seemed to be rising in a great commotion. And as he finished speaking two terrific detonations roared up from somewhere directly beneath them.

In an instant both men were on their feet and racing in headlong flight for the point where they had left the women.

“Get Joan!” shouted the Padre from behind. He was less swift of foot than Buck. “Get Joan! I’ll see to the other.”

Buck reached the girl’s side. She had heard the explosions of the underworld and stood shaking with terror.

“We’re up agin it, Joan,” he cried. And before the panic-stricken girl could reply she was in his strong young arms speeding for the downward path, which was their only hope.

“But the Padre! Aunt Mercy!” cried Joan, in a sudden recollection.

“They’re comin’ behind. He’ll see to her——God in heaven!”

A deafening roar, a hundred times greater than the first explosions, came from directly beneath the man’s feet. The air was full of it. To the fugitives it was as if the whole world had suddenly been riven asunder. For one flashing moment it seemed to Buck that he had been struck with fearful force from somewhere behind him, and as the blow fell he was hurled headlong down the precipitous path.

A confused, painful sense of cruel buffeting left him only half-conscious. There was a roar in his ears like the bombardment of unearthly artillery. It filled his brain to the exclusion of all else, while he hugged the girl close in his arms with some instinct of saving her, and shielding her from the cruel blows with his own body.