Meanwhile, Del Mar’s valet was leaving the bungalow and walking down the road on an errand for his master.  Up the road he heard the clatter of hoofs.  He stepped back off the road and from his covert he could see a squad of cavalry headed by the captain and a sailor cantering past.

The captain turned in the saddle to speak to the sailor, who rode like a horse marine, and as he did so, the turning of his body loosened a paper which he had stuffed quickly into his belt.  It fell to the ground.  In their hurry the troop, close behind, rode over it.  But it did not escape the quick eye of Del Mar’s valet.

They had scarcely disappeared around a bend in the road when he stepped out and pounced on the paper, reading it eagerly.  Every line of his face showed fear as he turned and ran back to the bungalow.

“See what I found,” he cried breathlessly bursting in on Del Mar who was seated at his desk, having returned from the harbor.

Del Mar read it with a scowl of fury.  Then he seized his hat, and a short hunter’s axe, and disappeared through the panel into the subterranean passage which took him by the shortest cut through the very hill to the shore.

Slowly Arnold and Woodward made their way along the shore, carefully searching for the spot where they had seen the house with the aerial.  At last they came to a place where they could see the deserted house, far up on the side of a ravine above a river and a waterfalls.  They dived into the thick underbrush for cover and went up the hill.

Some distance off from the house, they parted the bushes and gazed off across an open space at the ramshackle building.  As they looked they could see a man hurry across from the opposite direction and into the house.

“As I live, I think that’s Del Mar,” muttered Arnold.

Woodward nodded, doubtfully, though.

In the house, Del Mar hurried to a wall where he found and pressed a concealed spring.  A small cabinet in the plaster opened and he took out a little telephone which he rang and through which he spoke hastily.  “Pull in the wires,” he shouted.  “We’re discovered, I think.”

Down in the wireless station in the cave, the operator at his instrument heard the signal of the telephone and quickly answered it.  “All right, sir,” he returned with a look of great excitement and anxiety.  “Cut the wires and I’ll pull them in.”

Putting back the telephone, Del Mar ran to the window and looked out between the broken slats of the closed blinds.  “Confound them!” he muttered angrily.

He could see Arnold and Woodward cautiously approaching.  A moment later he stepped back and pulled a silk mask over his upper face, leaving only his eyes visible.  Then he seized his hunter’s axe and dashed up the stairs.  Through the scuttle of the roof he came, making his way over to the chimney to which the wireless antennae were fastened.

Hastily he cut the wires which ran through the roof from the aerial.  As he did so he saw them disappear through the roof.  Below, in the cave, down in the ravine back of the falls, the operator was hastily hauling in the wire Del Mar had cut.