Among the late arrivals were Woodward and his friend, Professor Arnold.

"I'm so glad to know that you are stationed at Fort Dale," greeted Elaine. "I hope it will be for all summer."

"I can't say how long it will be, but I shall make every effort to make it all summer," he replied gallantly. "Let me present my friend, Professor Arnold."

The professor bowed low and unprofessionally over Elaine's hand and a moment later followed Woodward out into the next room as the other guests arrived to be greeted by Elaine. For a moment, however, she looked after him curiously. Once she started to follow as though to speak to him. Just then, however, Del Mar entered.

"Good evening," he interrupted, suavely.

He stood for a moment with Elaine and talked.

One doorway in the house was draped and a tent had been erected in the room. Over the door was a sign which read: "The past and the future are an open book to Ancient Anna." There Aunt Josephine held forth in a most effective disguise as a fortune teller.

Aunt Josephine had always had a curious desire to play the old hag in amateur dramatics and now she had gratified her desire to the utmost.

Probably none of the guests knew that Ancient Anna was in reality Elaine's guardian.

Elaine being otherwise occupied, I had selected one of the prettiest of the girls and we were strolling through the house, seeking a quiet spot for a chat.

"Why don't you have your fortune told by Ancient Anna?" laughed my companion as we approached the tent.

"Do you tell a good fortune reasonably?" I joked, entering.

"Only the true fortunes, young man," returned Ancient Anna severely, starting in to read my palm. "You are very much in love," she went on, "but the lady is not in this tent."

Very much embarra.s.sed, I pulled my hand away.

"How shocking!" mocked my companion, making believe to be very much annoyed. "I don't think I'll have my fortune told," she decided as we left the room.

We sauntered along to the veranda where another friend claimed my companion for a dance which she had promised. As I strolled on alone, Del Mar and Elaine were already finishing a dance. He left her a moment later and I hurried over, glad of the opportunity to see her at last.

Del Mar made his way alone among the guests and pa.s.sed Aunt Josephine disguised as the old hag seated before her tent. Just then a waiter came through with a tray of ices. As he pa.s.sed, Del Mar stopped him, reached out and took an ice.

Under the ice, as he had known, was a note. He took the note surrept.i.tiously, turned and presented the ice to Ancient Anna with a bow.

"Thank you, kind sir," she curtsied, taking it.

Del Mar stepped aside and glanced at the little slip of paper. Then he crumpled it up and threw it aside, walking away.

No sooner had he gone than Aunt Josephine reached out and picked up the paper. She straightened it and looked at it. There was nothing on the paper but a crude drawing of a sunrise on the ocean.

"What's that?" asked Aunt Josephine, in surprise.

Just then Elaine and Lieutenant Woodward came in and stopped before the tent. Aunt Josephine motioned to Elaine to come in and Elaine followed.

Lieutenant Woodward started after her.

"No, no, young man," laughed Ancient Anna, shaking her forefinger at him, "I don't want you. It's the pretty young lady I want."

Woodward stood outside, though he did not know quite what it was all about. While he was standing there, Professor Arnold came up. He had not exactly made a hit with the guests. At least, he seemed to make little effort to do so. He and Woodward walked away, talking earnestly.

In the tent Aunt Josephine handed Elaine the piece of paper she had picked up.

"What does it mean?" asked Elaine, studying the curious drawing in surprise.

"I'm sure I don't know," confessed Aunt Josephine.

"Nor I."

Meanwhile Lieutenant Woodward and his friend had moved to a corner of the veranda and stood looking intently into the moonlight. There was Del Mar deep in conversation with a man who had slipped out, at a quiet signal, from his hiding-place in the shrubbery.

"That fellow is up to something, mark my words," muttered Arnold under his breath. "I'd like to make an arrest, but I've got to have some proof."

They continued watching Del Mar but, so far at least, he did nothing that would have furnished them any evidence of anything.

So the party went on, most merrily until, long after the guests had left, Elaine sat in her dressing-gown up in her room, about to retire.

Her maid had left her and she picked up the slip of paper from her dresser, looking at it thoughtfully.

"What can a crude drawing of a sunrise on the sea mean?" she asked herself.

For a long time she studied the paper, thinking it over. At last an idea came to her.

"I'll bet I have it," she exclaimed to herself. "Something is going to happen on the water at sunrise."

She took a pretty little alarm clock from the table, set it, and placed it near her bed.

Returning from the party to his library, Del Mar entered. Except for the moonlight streaming in through the windows the room was dark. He turned on the lights and crossed to the panel in the wall. As he touched a b.u.t.ton the panel opened. Del Mar switched off the lights and went through the panel, closing it.

Outside, at the other end of the pa.s.sageway, was one of his men, waiting in the shadows as Del Mar came up. For a moment they talked.

"I'll be there, at sunrise," agreed Del Mar, as the man left and he reentered the secret pa.s.sage.

While he was conferring, at the library window appeared a face. It was Professor Arnold's. Cautiously he opened the window and listened. Then he entered.

First he went over to the door and set a chair under the k.n.o.b. Next he drew an electric pocket bull's-eye and flashed it about the room. He glanced about and finally went over to Del Mar's desk where he examined a batch of letters, his back to the secret panel.

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 c.o.c.king 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.