There, on the day that Elaine decided to motor in from the city, Del Mar arrived with his valet.

Evidently he lost no time in getting to work on his own affairs, whatever they might be.  Inside his study, which was the largest room in the house, a combination of both library and laboratory, he gave an order or two to his valet, then immediately sat down to his new desk.  He opened a drawer and took out a long hollow cylinder, closed at each end by air-tight caps, on one of which was a hook.

Quickly he wrote a note and read it over:  “Install submarine bell in place of these clumsy tubes.  Am having harbor and bridges mined as per instructions from Government.  D.”

He unscrewed the cap at one end of the tube, inserted the note and closed it.  Then he pushed a button on his desk.  A panel in the wall opened and one of the men who had played policeman once for him stepped out and saluted.

“Here’s a message to send below,” said Del Mar briefly.

The man bowed and went back through the panel, closing it.

Del Mar cleaned up his desk and then went out to look his new quarters over, to see whether everything had been prepared according to his instructions.

From the concealed entrance to a cave on a hillside, Del Mar’s man who had gone through the panel in the bungalow appeared a few minutes later and hurried down to the shore.  It was a rocky coast with stretches of cliffs and now and then a ravine and bit of sandy beach.  Gingerly he climbed down the rocks to the water.

He took from his pocket the metal tube which Del Mar had given him and to the hook on one end attached a weight of lead.  A moment he looked about cautiously.  Then he threw the tube into the water and it sank quickly.  He did not wait, but hurried back into the cave entrance.

. . . . . . .

Elaine, Aunt Josephine and I motored down to Dodge Hall from the city.  Elaine’s country house was on a fine estate near the Long Island Sound and after the long run we were glad to pull up before the big house and get out of the car.  As we approached the door, I happened to look down the road.

“Well, that’s the country, all right,” I exclaimed, pointing down the road.  “Look.”

Lumbering along was a huge heavy hay rack on top of which perched a farmer chewing a straw.  Following along after him was a dog of a peculiar shepherd breed which I did not recognize.  Atop of the hay the old fellow had piled a trunk and a basket.

To our surprise the hay rack stopped before the house.  “Miss Dodge?” drawled the farmer nasally.

“Why, what do you suppose he can want?” asked Elaine moving out toward the wagon while we followed.  “Yes?”

“Here’s a trunk, Miss Dodge, with your name on it,” he went on dragging it down.  “I found it down by the railroad track.”

It was the trunk marked “E.  Dodge” which had been thrown off the train, taken by Del Mar and rifled by the motor-cyclist.