Arnold was running rapidly through the papers on the desk, as he flashed his electric bull’s-eye on them, when the panel in the wall opened slowly and Del Mar stepped into the room noiselessly.  To his surprise he saw a round spot of light from an electric flashlight focussed on his desk.  Some one was there!  He drew a gun.

Arnold started suddenly.  He heard the cocking of a revolver.  But he did not look around.  He merely thought an instant, quicker than lightning, then pulled out a spool of black thread with one hand, while with the other he switched off the light, and dived down on his stomach on the floor in the shadow.

“Who’s that?” demanded Del Mar.  “Confound it!  I should have fired at sight.”

The room was so dark now that it was impossible to see Arnold.  Del Mar gazed intently.  Suddenly Arnold’s electric torch glowed forth in a spot across the room.

Del Mar blazed at it, firing every chamber of his revolver, then switched on the lights.

No one was in the room.  But the door was open.  Del Mar gazed about, vexed, then ran to the open door.

For a second or two he peered out in rage, finally turning back into the empty room.  On the mantlepiece lay the torch of the intruder.  It was one in which the connection is made by a ring falling on a piece of metal.  The ring had been left up by Arnold.  Connection had been made as he was leaving the room by pulling the thread which he had fastened to the ring.  Del Mar followed the thread as it led around the room to the doorway.

“Curse him!” swore Del Mar, smashing down the innocent torch on the floor in fury, as he rushed to the desk and saw his papers all disturbed.

Outside, Arnold had made good his escape.  He paused in the moonlight and listened.  No one was pursuing.  He drew out two or three of the letters which he had taken from Del Mar’s desk, and hastily ran through them.

“Not a thing in them,” he exclaimed, tearing them up in disgust and hurrying away.

At the first break of dawn the little alarm dock awakened Elaine.  She started up and rubbed her eyes at the suddenness of the awakening, then quickly reached out and stopped the bell so that it would not disturb others in the house.  She jumped out of bed hurriedly and dressed.

Armed with a spy glass, Elaine let herself out of the house quietly.  Directly to the shore she went, walking along the beach.  Suddenly she paused.  There were three men.  Before she could level her glass at them, however, they disappeared.

“That’s strange,” she said to herself, looking through the glass.  “There’s a steamer at the dock that seems to be getting ready for something.  I wonder what it can be doing so early.”

She moved along in the direction of the dock.  At the dock the disreputable steamer to which Del Mar had dispatched his emissary was still tied, the sailors now working under the gruff orders of the rough captain.  About a capstan were wound the turns of a long wire rope at the end of which was a three-pronged drag-hook.