Slowly the cruiser came closer, heading right for the other ships of war in the harbor. Lord Hastings returned to his cabin and Frank followed him.

Jack continued to gaze over the rail at the cruiser. Suddenly, why he never knew, he rushed hurriedly after his commander.

"I am sure that is not a j.a.panese cruiser, sir," he cried. "I don't know why, but something tells me it is an enemy."

"Nonsense," said Lord Hastings again. "You are a bit nervous.

That's all."

"No, sir, it isn't that," replied Jack. "I--"

He was interrupted by the boom of a single big gun followed by a heavy outbreak of cannonading. Lord Hastings jumped to his feet and dashed to the bridge, Jack and Frank close at his heels.

They glanced quickly at the supposed j.a.panese cruiser. But the j.a.panese ensign had been hauled down, and now there floated from the cruiser the flag of Germany! And the cruiser's fourth smoke stack had come down.

"The Emden!" cried Lord Hastings.

Bugles were sounding on all the allied ships, of war in the harbor, calling the men to quarters. Caught thus unprepared, the allied vessels were at an immense disadvantage.

Suddenly there was a loud explosion aboard one of the Russian cruisers, and a moment later it burst into flames. Now the other ships poured broadsides into the Emden, but she stuck to her post. One of the two French destroyers suddenly dived, head-first, into the sea, one of the Emden's submerged torpedoes having dealt her a deathblow.

A sh.e.l.l sped over the stern of the Sylph, but did no damage.

Then, calmly, almost ignoring the remaining ships of the allied fleet, the Emden put about, and made off. Her raid had been successful, and it was another victory for the Kaiser.

The Emden continued to rain sh.e.l.ls at her foes until she was out of range. Not minded to take any unnecessary risk, Lord Hastings let the Emden get well out of range, before he gave the command for the Sylph to follow.

Then, stripped for action, the Sylph set out upon the trail of the German cruiser.

"We are on the trail at last," said Lord Hastings, "and on the trail we'll remain until the Emden has been sent to the bottom."

He turned to Jack. "Hereafter," he said, "I'll place faith in your premonitions."

The Sylph kept just far enough in the rear of the Emden to be out of range. After three hours, it became apparent that the commander of the German cruiser was aware that he was being followed. He slowed down, waiting the Sylph to come within range and give battle.

But while Lord Hastings was a brave man, he had no idea of accepting battle now. For had the day gone against him, the Emden would have been able to disappear once more. With the superior speed of the Sylph, Lord Hastings knew that he could remain on the trail, using his wireless to pick up some British vessel big enough to put an end to the "Terror of the Sea."

Accordingly, the Sylph also slowed down. After waiting in vain for the little scout cruiser to approach closer, the Emden again set out on her course, at full speed. The Sylph also quickened her pace, and the Emden was unable to shake her off.

Then the Emden slowed down again. So did the Sylph. The wireless operator approached Lord Hastings with a message.

Lord Hastings read it aloud:

"Remain where you are till I come up, or I shall sink you.

Signed, von Mueller."

Followed by the two lads Lord Hastings made his way to the wireless room, and ticked off this message himself:

"The Emden is doomed. Signed, Hastings."

CHAPTER XXI

ON THE TRAIL

A reply to this message was not long coming. It read:

"Lord Hastings: Sorry you are aboard, but I must sink you."

To this Lord Hastings replied:

"It can't be done."

Now the Emden put about and headed for the Sylph. Quickly also the Sylph came about and headed westward.

"If he'll only follow long enough, we'll lure him into the path of some British vessel," said Lord Hastings.

"Well," said Jack, "I don't believe he will. As soon as he finds he cannot overtake us, he'll continue on his way."

"And he'll try to lose us in the night," said Frank.

"That is my idea," said Lord Hastings. "To prevent that we must be on the alert continually. We'll follow him for months, if necessary. At nights we shall have to close up a bit, and take a chance that they cannot hit us."

It was nearing dusk when the Emden finally gave up the chase of the Sylph as futile, and once more put about. Immediately also the Sylph's head came about, and she once more set out, to trail the German. Occasional messages were exchanged between Captain von Mueller and Lord Hastings.

Night fell, and now the Sylph began to draw closer to her quarry.

She closed up the distance gradually, until Lord Hastings decided that they were near enough; and this position the Sylph maintained, her searchlight playing upon the Emden and making her as light as day.

All night and all the following day the Sylph followed the Emden.

Several times the Emden put about, and made as if to give chase, but on each occasion the Sylph also changed her course. The relative positions of the two vessels remained the same, except that in the light of day the Sylph put more distance between her and her quarry.

Night drew on once more, and again the Sylph approached closer.

It was plain that this remorseless pursuit was worrying the commander of the Emden and that he did not know which way to turn to avoid his pursuer.

Lord Hastings sniffed the air.

"Feels like there would be a fog tonight," he said. "I hope it is not so dense as to dim the glow of the searchlight."

But in this he was doomed to disappointment. The fog descended, but still those on the Sylph could dimly make out the outline of the Emden. But with the approach of morning, while Jack had the bridge, the fog suddenly thickened, and blotted out the pursued vessel entirely.

Quickly Jack summoned Lord Hastings.

Immediately Lord Hastings ordered the searchlight extinguished and all lights on board put out.

"We don't want to let him know where we are," he said. "I feel absolutely certain that Captain von Mueller will double back and try to come up upon us in the fog. We must avoid that at all hazards, and at the same time must so maneuver as to be near enough to pick him up when the fog lifts."

Lord Hastings altered the course of the Sylph slightly, but continued to go forward. Six o'clock came and no sign of the Emden, and then seven. And then the fog lifted as suddenly as it had descended, and at that moment there was the sound of a big gun and a sh.e.l.l whistled over the stern of the Sylph.