Viciously next, Del Mar fell upon the wooden aerial itself, chopping it right and left with powerful blows.  He broke it off and threw it over the roof.

Below, Arnold and Woodward, taking advantage of every tree and shrub for concealment, had almost reached the house when the broken aerial fell with a bang almost on them.  In surprise they dropped back of a tree and looked up.  But from their position they could see nothing.  Together they drew their guns and advanced more cautiously at the house.

Del Mar made his way back quickly over the roof, back through the scuttle and down the stairs again.  Should he go out?  He looked out of the window.  Then he went to the door.  An instant he paused thinking and listening, his axe raised, ready for a blow.

Arnold and Woodward, by this time, had reached the door which swung open on its rusty hinges.  Woodward was about to go in when he felt a hand on his arm.

“Wait,” cautioned Arnold.  He took off his hat and jammed it on the end of a stick.  Slowly he shoved the door open, then thrust the hat and stick just a fraction of a foot forward.

Del Mar, waiting, alert, saw the door open and a hat.  He struck at it hard with the axe and merely the hat and stick fell to the floor.

“Now, come on,” shouted Arnold to Woodward.

In the other hand, Del Mar held a chair.  As Woodward dashed in with Arnold beside him, Del Mar shied the chair at their feet.  Woodward fell over it in a heap and as he did so the delay was all that Del Mar had hoped to gain.  Without a second’s hesitation he dived through an open window, just as Arnold ran forward, avoiding Woodward and the chair.  It was spectacular, but it worked.  Arnold fired, but even that was not quick enough.  He turned and with Woodward who had picked himself up in spite of his barked shins and they ran back through the door by which they had entered.

Recovering himself, Del Mar dashed for the woods just as Arnold and Woodward ran around the side of the house, still blazing away after him, as they followed, rapidly gaining.

Elaine changed her clothes quickly.  Meanwhile she had ordered horses for both of us and a groom brought them around from the stables.  It took me only a short time to jump into some dry things and I waited impatiently.

She was ready very soon, however, and we mounted and cantered off, again in the direction of the shore where she had seen the remarkable waterfall, of which she had told me.

We had not gone far when we heard sounds, as if an army were bearing down on us.  “What’s that?” I asked.

Elaine turned and looked.  It was a squad of cavalry.

“Why, it’s Lieutenant Woodward’s friend, Captain Price,” she exclaimed, waving to the captain at the head of the squad.

A moment later Captain Price pulled up and bowed.  Quickly we told him of what Elaine had just discovered.

“That’s strange,” he said.  “This man—­” indicating the sailor—­ “has just told me that Lieutenant Woodward and Professor Arnold are investigating a wireless outfit over near there.  Perhaps there’s some connection.”