He had found and seized by the coat collar the man with the green hat.

Dave and Dan rushed to the spot, hardly knowing what they could do, as they did not want to see the representative of the American State Department lack for backing.

"Pull Cushing away from that fellow," ordered Totten.

"Is that an official order?" Dave flashed back, in a whisper.

"It is," nodded Totten, and faded back into the blackness of the night.

Dave bounded forward. He saw that the launch was one belonging to some liner or merchant ship in the harbor. Three or four men belonging in that launch had leaped to the rescue of Mr. Green Hat. Dave, with one tug, tore Cushing away.

Mr. Green Hat fell back in the launch. Two sailors belonging to that craft cast off the lines at bow and stern, and the launch glided out into the harbor.

"Why didn't you help me, instead of putting the double cross on me?"

Cushing demanded, angrily.

"I had my reasons," Ensign Darrin replied, briefly.

"They must have been good ones," muttered Cushing.

"All aboard for the flagship!" announced Lieutenant Totten, in a quiet tone.

"Come along, if you're going out with us," Darrin urged Cushing.

The pa.s.sengers for the flagship launch were speedily aboard. Other officers were there who had been ash.o.r.e for the evening.

As the launch was cast off she glided almost noiselessly across the smooth water of the harbor, followed closely by the shifting rays of a British searchlight on sh.o.r.e. Ever since the great European war had started searchlights stationed on sh.o.r.e had followed the movements of every craft in the harbor at night. Beyond, the flagship's few lights glowed brightly. In a few minutes the party was alongside.

Dave and Dan, after saluting the officer of the deck, and reporting their presence on board, went at once to Dave's quarters.

"There was a good deal of a mix-up, somewhere," Dan announced, at once. "Why should Totten order you to drag Cushing away from Mr. Green Hat, when that rascal had robbed Cushing of valuable government papers?"

"It's too big a puzzle for me," Ensign Darrin admitted, promptly. "But Lieutenant Totten is my superior officer, and the responsibility belongs to him."

For a few minutes the two chums chatted. Dalzell was about to say good night and go to his own quarters, when an orderly rapped at the door, then entered, saluting.

"The admiral's compliments, gentlemen," said the messenger. "The admiral wishes to see Ensigns Darrin and Dalzell at once."

"Our compliments, and we will report at once," Dave answered. Both young officers were now in uniform, for Dan had left his in Dave's quarters before going ash.o.r.e, and the chums had changed their clothes while chatting. It now remained only for Dave to reach for his sword and fasten it on, then draw on white gloves, while Dalzell went to his quarters, next door, and did the same.

"What can be in the wind?" whispered Dan. "This is the first time that Admiral Timworth has ever expressed any desire to see us. Can it be that we bungled in some way with the Cushing business?"

"I'm not going to waste any time in guessing," replied Ensign Darrin, as they stepped briskly along, "when I'm going to have the answer presented to me so soon."

Then they halted before the entrance to the admiral's quarters, to learn if it would be agreeable for the admiral to receive them at once.

CHAPTER II

DAN'S THIRTY-THREE-DOLLAR GUESS

As the two young officers entered the admiral's quarters the curtains were closed behind them by the marine orderly.

Admiral Timworth was seated at his desk. Beside him was Captain Allen, commanding officer of the battleship "Hudson," flagship of the Mediterranean Squadron.

Lieutenant Totten and Cushing were also present.

"Good evening, gentlemen," was Admiral Timworth's greeting, after salutes had been exchanged. "Accidentally, you became spectators this evening, at a little drama connected with both the diplomatic and the secret service of your country."

The admiral paused, but both young officers remained respectfully at attention, making no response, as none was needed.

"You are aware," continued the admiral, "that Mr. Cushing was knocked down and robbed of an important government paper. Now, it happens that this paper was the key to a code employed by the State and Navy Departments in communicating with naval commanders abroad."

This time Dave actually started. The loss of such a code would be vitally important. The State and Navy Departments almost invariably communicate with naval commanders by means of a secret code, which can be read only by commanders possessing the key. Thus, when cablegrams are sent from stations in foreign countries, their import can be understood only by the officers to whom the communications are addressed.

"That strikes you as a most serious loss, does it not?" asked Admiral Timworth, smiling.

"Why, yes, sir; so it would seem," Dave answered, bowing.

"The code that was stolen to-night," laughed the admiral, "will be of but little value to the government into whose hands it may fall. The code in question was one that was used in the year 1880, and has not been employed since. Nor is it likely ever to be employed again."

Captain Allen joined in the admiral's laugh.

"We had every reason," continued the admiral, "to believe that an attempt would be made to steal that code ere Mr. Cushing delivered it to me. In fact, our government allowed it to be rather widely known that Mr. Cushing had left Washington to turn over to me a code. So, of course, Mr. Cushing has been followed. As a matter of fact, the code that we have been using for the last six months has not been changed.

I was delighted when I learned that Cushing had been a.s.saulted and robbed. Mr. Cushing himself took the loss seriously, for he did not know, until he came aboard a few moments ago, that the United States government had hoped he _would_ be robbed. Lieutenant Totten was sent ash.o.r.e, ostensibly to look after the launch, but in reality, to learn, if possible, whether Cushing's a.s.sailant put off in the launch of another power, and if so, which power. Ensigns Darrin and Dalzell, you noted, did you not, the nationality of the launch in which Mr.

Cushing's a.s.sailant escaped?"

"I did not, sir," Dave replied. "It was not a naval launch, and therefore did not belong to any ships belonging to the Entente Allies'

naval vessels in port here."

"Then, gentlemen," continued Admiral Timworth, his voice in tones of formal command, "you will not at any time mention this matter to any one unless so directed by me. I have had just one object in sending for you and giving you this order. For some time our Government has known that secret efforts are being made to discredit us with the allied powers of Europe. I feel rather certain that this fleet, while in the Mediterranean, will be closely watched by plotters serving one of the Central European powers, or else acting on their own account in the hope of being able to succeed and then claim reward from that government. Keep your eyes open. You may meet other spies and have reason to suspect them to be such. Do not be fooled by the apparent nationality of any man's name. A spy uses many names in his course around the world. Few international spies ever use their own names.

The man in the green hat, who a.s.saulted Mr. Cushing to-night, is one of the cleverest of his kind, and perhaps the most able with whom we shall have to contend. The fellow's name is supposed to be Emil Gortchky. At one time or another he has served as spy for nearly every government in Europe. He is a daring, dangerous, and wholly unscrupulous fellow. Ensigns Darrin and Dalzell, I sent for you in order to tell you these things, and to add that if, during this cruise, you run across the fellow at any point, you are to report the fact to me promptly. Of course you will understand that the seal of official secrecy attaches to all that I have said. That is all, gentlemen. Good evening."

Saluting, Ensigns Darrin and Dalzell promptly withdrew. They were still a good deal puzzled.

"I'll come to your quarters in a minute, if I may," murmured Danny Grin, as he reached the door of his own cabin.

"I want you to come," Dave answered dryly.

So, in another minute, Dan Dalzell, minus sword and gloves, bobbed into Dave's room.

"Now, what do you make out of all we have heard and seen?" breathed Dalzell tensely.

"Just what the admiral told us," answered Darrin.